From e16a278a51f1a60bebf96c81df4acd2f8aadec4e Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 10:54:42 +0000
Subject: [PATCH 01/10] test: initialize type tests

---
 examples/cat.ts          |   2 +-
 package.json             |   6 +-
 test-d/command.test-d.ts |   6 +
 test-d/program.test-d.ts |   6 +
 tests/program.spec.ts    |   4 +-
 yarn.lock                | 491 +++++++++++++++++++++++++++++++++++++--
 6 files changed, 496 insertions(+), 19 deletions(-)
 create mode 100644 test-d/command.test-d.ts
 create mode 100644 test-d/program.test-d.ts

diff --git a/examples/cat.ts b/examples/cat.ts
index 411fce97..1e2f8713 100644
--- a/examples/cat.ts
+++ b/examples/cat.ts
@@ -3,7 +3,7 @@ import { command, program } from '../src'
 
 const cat = command('cat')
   .description('Concatenate files')
-  .argument('files', { variadic: true })
+  .argument('files', { variadic: true, default: [] })
   .action(({ files }) =>
     console.log(
       files.reduce((str, file) => str + readFileSync(file, 'utf8'), '')
diff --git a/package.json b/package.json
index de69d5d8..69e87376 100644
--- a/package.json
+++ b/package.json
@@ -22,12 +22,13 @@
   "files": [
     "lib"
   ],
+  "types": "lib/index.d.ts",
   "scripts": {
     "prepublishOnly": "yarn build",
     "build": "tsc",
     "watch": "tsc --watch",
     "lint": "prettier --write \"src/**/*\"",
-    "test": "jest",
+    "test": "tsd && jest",
     "start": "ts-node",
     "doc:toc": "doctoc README.md",
     "doc:todos": "leasot --exit-nicely --reporter markdown \"src/**/*.ts\" > TODO.md"
@@ -57,6 +58,7 @@
     "prettier": "2.6.0",
     "ts-jest": "27.1.3",
     "ts-node": "10.7.0",
+    "tsd": "^0.19.1",
     "typescript": "4.6.2"
   }
-}
+}
\ No newline at end of file
diff --git a/test-d/command.test-d.ts b/test-d/command.test-d.ts
new file mode 100644
index 00000000..1caf995c
--- /dev/null
+++ b/test-d/command.test-d.ts
@@ -0,0 +1,6 @@
+import { expectType } from 'tsd'
+import { Command, command } from '../src/command'
+
+const cmd = command()
+
+expectType<Command>(cmd)
diff --git a/test-d/program.test-d.ts b/test-d/program.test-d.ts
new file mode 100644
index 00000000..333ddb47
--- /dev/null
+++ b/test-d/program.test-d.ts
@@ -0,0 +1,6 @@
+import { expectType } from 'tsd'
+import { Program, program } from '../src/program'
+
+const app = program()
+
+expectType<Program>(app)
diff --git a/tests/program.spec.ts b/tests/program.spec.ts
index ecbb122e..80a9a0f2 100644
--- a/tests/program.spec.ts
+++ b/tests/program.spec.ts
@@ -1,6 +1,4 @@
-// @ts-ignore
 import mockArgv from 'mock-argv'
-import { mocked } from 'ts-jest/utils'
 import { command, program, Program, Repl } from '../src'
 
 jest.mock('../src/repl', () => {
@@ -22,7 +20,7 @@ class MockedRepl {
 }
 
 beforeEach(() => {
-  const MockedRepl = mocked(Repl, true)
+  const MockedRepl = jest.mocked(Repl, true)
   MockedRepl.mockClear()
 })
 
diff --git a/yarn.lock b/yarn.lock
index f8aa9a9f..fb87e6d4 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1275,6 +1275,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@tsd/typescript@npm:~4.5.2":
+  version: 4.5.5
+  resolution: "@tsd/typescript@npm:4.5.5"
+  bin:
+    tsc: typescript/bin/tsc
+    tsserver: typescript/bin/tsserver
+  checksum: 6b57a087b713530966f073b47837c47a52adf7f4b036495853283ff0a6d7b39ec6d6a59105ca4708bb715f7a8551f4dd004de20ca0b72c396103c360841b6aab
+  languageName: node
+  linkType: hard
+
 "@types/babel__core@npm:^7.0.0":
   version: 7.1.9
   resolution: "@types/babel__core@npm:7.1.9"
@@ -1345,6 +1355,23 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/eslint@npm:^7.2.13":
+  version: 7.29.0
+  resolution: "@types/eslint@npm:7.29.0"
+  dependencies:
+    "@types/estree": "*"
+    "@types/json-schema": "*"
+  checksum: df13991c554954353ce8f3bb03e19da6cc71916889443d68d178d4f858b561ba4cc4a4f291c6eb9eebb7f864b12b9b9313051b3a8dfea3e513dadf3188a77bdf
+  languageName: node
+  linkType: hard
+
+"@types/estree@npm:*":
+  version: 0.0.51
+  resolution: "@types/estree@npm:0.0.51"
+  checksum: e56a3bcf759fd9185e992e7fdb3c6a5f81e8ff120e871641607581fb3728d16c811702a7d40fa5f869b7f7b4437ab6a87eb8d98ffafeee51e85bbe955932a189
+  languageName: node
+  linkType: hard
+
 "@types/graceful-fs@npm:^4.1.2":
   version: 4.1.3
   resolution: "@types/graceful-fs@npm:4.1.3"
@@ -1389,6 +1416,20 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/json-schema@npm:*":
+  version: 7.0.10
+  resolution: "@types/json-schema@npm:7.0.10"
+  checksum: 369f12207298e3c8931100ab86c9c60d9217ab930a8ae0b851495f4f30695d3f0eb431eedc8e8d9c69357869899ea0fe6f9d65ddde5ea70415d67ef340dfdd1f
+  languageName: node
+  linkType: hard
+
+"@types/minimist@npm:^1.2.0":
+  version: 1.2.2
+  resolution: "@types/minimist@npm:1.2.2"
+  checksum: b8da83c66eb4aac0440e64674b19564d9d86c80ae273144db9681e5eeff66f238ade9515f5006ffbfa955ceff8b89ad2bd8ec577d7caee74ba101431fb07045d
+  languageName: node
+  linkType: hard
+
 "@types/node@npm:*":
   version: 14.0.26
   resolution: "@types/node@npm:14.0.26"
@@ -1403,6 +1444,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/normalize-package-data@npm:^2.4.0":
+  version: 2.4.1
+  resolution: "@types/normalize-package-data@npm:2.4.1"
+  checksum: e87bccbf11f95035c89a132b52b79ce69a1e3652fe55962363063c9c0dae0fe2477ebc585e03a9652adc6f381d24ba5589cc5e51849df4ced3d3e004a7d40ed5
+  languageName: node
+  linkType: hard
+
 "@types/prettier@npm:^2.1.5":
   version: 2.2.3
   resolution: "@types/prettier@npm:2.2.3"
@@ -1682,6 +1730,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"arrify@npm:^1.0.1":
+  version: 1.0.1
+  resolution: "arrify@npm:1.0.1"
+  checksum: 745075dd4a4624ff0225c331dacb99be501a515d39bcb7c84d24660314a6ec28e68131b137e6f7e16318170842ce97538cd298fc4cd6b2cc798e0b957f2747e7
+  languageName: node
+  linkType: hard
+
 "async@npm:^3.2.0":
   version: 3.2.0
   resolution: "async@npm:3.2.0"
@@ -1813,6 +1868,7 @@ __metadata:
     string-argv: ^0.3.1
     ts-jest: 27.1.3
     ts-node: 10.7.0
+    tsd: ^0.19.1
     typed-emitter: ^1.3.1
     typescript: 4.6.2
     yargs: ^17.1.1
@@ -1939,6 +1995,17 @@ __metadata:
   languageName: node
   linkType: hard
 
+"camelcase-keys@npm:^6.2.2":
+  version: 6.2.2
+  resolution: "camelcase-keys@npm:6.2.2"
+  dependencies:
+    camelcase: ^5.3.1
+    map-obj: ^4.0.0
+    quick-lru: ^4.0.1
+  checksum: 43c9af1adf840471e54c68ab3e5fe8a62719a6b7dbf4e2e86886b7b0ff96112c945736342b837bd2529ec9d1c7d1934e5653318478d98e0cf22c475c04658e2a
+  languageName: node
+  linkType: hard
+
 "camelcase@npm:^5.3.1":
   version: 5.3.1
   resolution: "camelcase@npm:5.3.1"
@@ -2241,6 +2308,23 @@ __metadata:
   languageName: node
   linkType: hard
 
+"decamelize-keys@npm:^1.1.0":
+  version: 1.1.0
+  resolution: "decamelize-keys@npm:1.1.0"
+  dependencies:
+    decamelize: ^1.1.0
+    map-obj: ^1.0.0
+  checksum: 8bc5d32e035a072f5dffc1f1f3d26ca7ab1fb44a9cade34c97ab6cd1e62c81a87e718101e96de07d78cecda20a3fdb955df958e46671ccad01bb8dcf0de2e298
+  languageName: node
+  linkType: hard
+
+"decamelize@npm:^1.1.0, decamelize@npm:^1.2.0":
+  version: 1.2.0
+  resolution: "decamelize@npm:1.2.0"
+  checksum: ad8c51a7e7e0720c70ec2eeb1163b66da03e7616d7b98c9ef43cce2416395e84c1e9548dd94f5f6ffecfee9f8b94251fc57121a8b021f2ff2469b2bae247b8aa
+  languageName: node
+  linkType: hard
+
 "decimal.js@npm:^10.2.1":
   version: 10.2.1
   resolution: "decimal.js@npm:10.2.1"
@@ -2529,6 +2613,29 @@ __metadata:
   languageName: node
   linkType: hard
 
+"eslint-formatter-pretty@npm:^4.1.0":
+  version: 4.1.0
+  resolution: "eslint-formatter-pretty@npm:4.1.0"
+  dependencies:
+    "@types/eslint": ^7.2.13
+    ansi-escapes: ^4.2.1
+    chalk: ^4.1.0
+    eslint-rule-docs: ^1.1.5
+    log-symbols: ^4.0.0
+    plur: ^4.0.0
+    string-width: ^4.2.0
+    supports-hyperlinks: ^2.0.0
+  checksum: e8e0cd3843513fff32a70b036dd349fdab81d73b5e522f23685181c907a1faf2b2ebcae1688dc71d0fc026184011792f7e39b833d349df18fe2baea00d017901
+  languageName: node
+  linkType: hard
+
+"eslint-rule-docs@npm:^1.1.5":
+  version: 1.1.231
+  resolution: "eslint-rule-docs@npm:1.1.231"
+  checksum: b776c75469bf392d58747e2ffa12e96041f7fef00d6b6c7d5e1a3f3621e42fdde4811795eb7cd4c429c33ef71b9d84f5822d58bca8964e2814485f2498be77b5
+  languageName: node
+  linkType: hard
+
 "esprima@npm:^4.0.0, esprima@npm:^4.0.1":
   version: 4.0.1
   resolution: "esprima@npm:4.0.1"
@@ -2610,6 +2717,19 @@ __metadata:
   languageName: node
   linkType: hard
 
+"fast-glob@npm:^3.2.9":
+  version: 3.2.11
+  resolution: "fast-glob@npm:3.2.11"
+  dependencies:
+    "@nodelib/fs.stat": ^2.0.2
+    "@nodelib/fs.walk": ^1.2.3
+    glob-parent: ^5.1.2
+    merge2: ^1.3.0
+    micromatch: ^4.0.4
+  checksum: f473105324a7780a20c06de842e15ddbb41d3cb7e71d1e4fe6e8373204f22245d54f5ab9e2061e6a1c613047345954d29b022e0e76f5c28b1df9858179a0e6d7
+  languageName: node
+  linkType: hard
+
 "fast-json-stable-stringify@npm:2.x, fast-json-stable-stringify@npm:^2.0.0":
   version: 2.1.0
   resolution: "fast-json-stable-stringify@npm:2.1.0"
@@ -2808,6 +2928,15 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"glob-parent@npm:^5.1.2":
+  version: 5.1.2
+  resolution: "glob-parent@npm:5.1.2"
+  dependencies:
+    is-glob: ^4.0.1
+  checksum: f4f2bfe2425296e8a47e36864e4f42be38a996db40420fe434565e4480e3322f18eb37589617a98640c5dc8fdec1a387007ee18dbb1f3f5553409c34d17f425e
+  languageName: node
+  linkType: hard
+
 "glob@npm:^7.1.1, glob@npm:^7.1.2, glob@npm:^7.1.3, glob@npm:^7.1.4":
   version: 7.1.6
   resolution: "glob@npm:7.1.6"
@@ -2829,6 +2958,20 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"globby@npm:^11.0.1":
+  version: 11.1.0
+  resolution: "globby@npm:11.1.0"
+  dependencies:
+    array-union: ^2.1.0
+    dir-glob: ^3.0.1
+    fast-glob: ^3.2.9
+    ignore: ^5.2.0
+    merge2: ^1.4.1
+    slash: ^3.0.0
+  checksum: b4be8885e0cfa018fc783792942d53926c35c50b3aefd3fdcfb9d22c627639dc26bd2327a40a0b74b074100ce95bb7187bfeae2f236856aa3de183af7a02aea6
+  languageName: node
+  linkType: hard
+
 "globby@npm:^11.0.3":
   version: 11.0.3
   resolution: "globby@npm:11.0.3"
@@ -2864,6 +3007,13 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"hard-rejection@npm:^2.1.0":
+  version: 2.1.0
+  resolution: "hard-rejection@npm:2.1.0"
+  checksum: 7baaf80a0c7fff4ca79687b4060113f1529589852152fa935e6787a2bc96211e784ad4588fb3048136ff8ffc9dfcf3ae385314a5b24db32de20bea0d1597f9dc
+  languageName: node
+  linkType: hard
+
 "has-flag@npm:^3.0.0":
   version: 3.0.0
   resolution: "has-flag@npm:3.0.0"
@@ -2894,6 +3044,22 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"hosted-git-info@npm:^2.1.4":
+  version: 2.8.9
+  resolution: "hosted-git-info@npm:2.8.9"
+  checksum: c955394bdab888a1e9bb10eb33029e0f7ce5a2ac7b3f158099dc8c486c99e73809dca609f5694b223920ca2174db33d32b12f9a2a47141dc59607c29da5a62dd
+  languageName: node
+  linkType: hard
+
+"hosted-git-info@npm:^4.0.1":
+  version: 4.1.0
+  resolution: "hosted-git-info@npm:4.1.0"
+  dependencies:
+    lru-cache: ^6.0.0
+  checksum: c3f87b3c2f7eb8c2748c8f49c0c2517c9a95f35d26f4bf54b2a8cba05d2e668f3753548b6ea366b18ec8dadb4e12066e19fa382a01496b0ffa0497eb23cbe461
+  languageName: node
+  linkType: hard
+
 "html-encoding-sniffer@npm:^2.0.1":
   version: 2.0.1
   resolution: "html-encoding-sniffer@npm:2.0.1"
@@ -3000,6 +3166,13 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"ignore@npm:^5.2.0":
+  version: 5.2.0
+  resolution: "ignore@npm:5.2.0"
+  checksum: 6b1f926792d614f64c6c83da3a1f9c83f6196c2839aa41e1e32dd7b8d174cef2e329d75caabb62cb61ce9dc432f75e67d07d122a037312db7caa73166a1bdb77
+  languageName: node
+  linkType: hard
+
 "import-local@npm:^3.0.2":
   version: 3.0.2
   resolution: "import-local@npm:3.0.2"
@@ -3057,6 +3230,13 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"irregular-plurals@npm:^3.2.0":
+  version: 3.3.0
+  resolution: "irregular-plurals@npm:3.3.0"
+  checksum: 1282d8adfb00a9718655ce21e5b096d4b31d2115c817a30e1e3254648ae4ac0f84d706cd0cad2a93c64f4bb5c5572ea8f63fcc9766f005a5362031c56d9e77b5
+  languageName: node
+  linkType: hard
+
 "is-alphabetical@npm:^1.0.0":
   version: 1.0.4
   resolution: "is-alphabetical@npm:1.0.4"
@@ -3108,6 +3288,15 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"is-core-module@npm:^2.5.0, is-core-module@npm:^2.8.1":
+  version: 2.8.1
+  resolution: "is-core-module@npm:2.8.1"
+  dependencies:
+    has: ^1.0.3
+  checksum: 418b7bc10768a73c41c7ef497e293719604007f88934a6ffc5f7c78702791b8528102fb4c9e56d006d69361549b3d9519440214a74aefc7e0b79e5e4411d377f
+  languageName: node
+  linkType: hard
+
 "is-decimal@npm:^1.0.0":
   version: 1.0.4
   resolution: "is-decimal@npm:1.0.4"
@@ -3913,6 +4102,13 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"kind-of@npm:^6.0.3":
+  version: 6.0.3
+  resolution: "kind-of@npm:6.0.3"
+  checksum: 3ab01e7b1d440b22fe4c31f23d8d38b4d9b91d9f291df683476576493d5dfd2e03848a8b05813dd0c3f0e835bc63f433007ddeceb71f05cb25c45ae1b19c6d3b
+  languageName: node
+  linkType: hard
+
 "kleur@npm:^3.0.3":
   version: 3.0.3
   resolution: "kleur@npm:3.0.3"
@@ -3996,7 +4192,7 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
-"log-symbols@npm:^4.1.0":
+"log-symbols@npm:^4.0.0, log-symbols@npm:^4.1.0":
   version: 4.1.0
   resolution: "log-symbols@npm:4.1.0"
   dependencies:
@@ -4063,6 +4259,20 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"map-obj@npm:^1.0.0":
+  version: 1.0.1
+  resolution: "map-obj@npm:1.0.1"
+  checksum: 9949e7baec2a336e63b8d4dc71018c117c3ce6e39d2451ccbfd3b8350c547c4f6af331a4cbe1c83193d7c6b786082b6256bde843db90cb7da2a21e8fcc28afed
+  languageName: node
+  linkType: hard
+
+"map-obj@npm:^4.0.0":
+  version: 4.3.0
+  resolution: "map-obj@npm:4.3.0"
+  checksum: fbc554934d1a27a1910e842bc87b177b1a556609dd803747c85ece420692380827c6ae94a95cce4407c054fa0964be3bf8226f7f2cb2e9eeee432c7c1985684e
+  languageName: node
+  linkType: hard
+
 "markdown-escapes@npm:^1.0.0":
   version: 1.0.4
   resolution: "markdown-escapes@npm:1.0.4"
@@ -4070,6 +4280,26 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"meow@npm:^9.0.0":
+  version: 9.0.0
+  resolution: "meow@npm:9.0.0"
+  dependencies:
+    "@types/minimist": ^1.2.0
+    camelcase-keys: ^6.2.2
+    decamelize: ^1.2.0
+    decamelize-keys: ^1.1.0
+    hard-rejection: ^2.1.0
+    minimist-options: 4.1.0
+    normalize-package-data: ^3.0.0
+    read-pkg-up: ^7.0.1
+    redent: ^3.0.0
+    trim-newlines: ^3.0.0
+    type-fest: ^0.18.0
+    yargs-parser: ^20.2.3
+  checksum: 99799c47247f4daeee178e3124f6ef6f84bde2ba3f37652865d5d8f8b8adcf9eedfc551dd043e2455cd8206545fd848e269c0c5ab6b594680a0ad4d3617c9639
+  languageName: node
+  linkType: hard
+
 "merge-stream@npm:^2.0.0":
   version: 2.0.0
   resolution: "merge-stream@npm:2.0.0"
@@ -4077,7 +4307,7 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
-"merge2@npm:^1.3.0":
+"merge2@npm:^1.3.0, merge2@npm:^1.4.1":
   version: 1.4.1
   resolution: "merge2@npm:1.4.1"
   checksum: 7268db63ed5169466540b6fb947aec313200bcf6d40c5ab722c22e242f651994619bcd85601602972d3c85bd2cc45a358a4c61937e9f11a061919a1da569b0c2
@@ -4127,6 +4357,13 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"min-indent@npm:^1.0.0":
+  version: 1.0.1
+  resolution: "min-indent@npm:1.0.1"
+  checksum: bfc6dd03c5eaf623a4963ebd94d087f6f4bbbfd8c41329a7f09706b0cb66969c4ddd336abeb587bc44bc6f08e13bf90f0b374f9d71f9f01e04adc2cd6f083ef1
+  languageName: node
+  linkType: hard
+
 "minimatch@npm:^3.0.4":
   version: 3.0.4
   resolution: "minimatch@npm:3.0.4"
@@ -4136,6 +4373,17 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"minimist-options@npm:4.1.0":
+  version: 4.1.0
+  resolution: "minimist-options@npm:4.1.0"
+  dependencies:
+    arrify: ^1.0.1
+    is-plain-obj: ^1.1.0
+    kind-of: ^6.0.3
+  checksum: 8c040b3068811e79de1140ca2b708d3e203c8003eb9a414c1ab3cd467fc5f17c9ca02a5aef23bedc51a7f8bfbe77f87e9a7e31ec81fba304cda675b019496f4e
+  languageName: node
+  linkType: hard
+
 "minimist@npm:^1.2.5, minimist@npm:~1.2.5":
   version: 1.2.5
   resolution: "minimist@npm:1.2.5"
@@ -4302,6 +4550,30 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"normalize-package-data@npm:^2.5.0":
+  version: 2.5.0
+  resolution: "normalize-package-data@npm:2.5.0"
+  dependencies:
+    hosted-git-info: ^2.1.4
+    resolve: ^1.10.0
+    semver: 2 || 3 || 4 || 5
+    validate-npm-package-license: ^3.0.1
+  checksum: 7999112efc35a6259bc22db460540cae06564aa65d0271e3bdfa86876d08b0e578b7b5b0028ee61b23f1cae9fc0e7847e4edc0948d3068a39a2a82853efc8499
+  languageName: node
+  linkType: hard
+
+"normalize-package-data@npm:^3.0.0":
+  version: 3.0.3
+  resolution: "normalize-package-data@npm:3.0.3"
+  dependencies:
+    hosted-git-info: ^4.0.1
+    is-core-module: ^2.5.0
+    semver: ^7.3.4
+    validate-npm-package-license: ^3.0.1
+  checksum: bbcee00339e7c26fdbc760f9b66d429258e2ceca41a5df41f5df06cc7652de8d82e8679ff188ca095cad8eff2b6118d7d866af2b68400f74602fbcbce39c160a
+  languageName: node
+  linkType: hard
+
 "normalize-path@npm:^3.0.0":
   version: 3.0.0
   resolution: "normalize-path@npm:3.0.0"
@@ -4438,7 +4710,7 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
-"parse-json@npm:^5.2.0":
+"parse-json@npm:^5.0.0, parse-json@npm:^5.2.0":
   version: 5.2.0
   resolution: "parse-json@npm:5.2.0"
   dependencies:
@@ -4485,6 +4757,13 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"path-parse@npm:^1.0.7":
+  version: 1.0.7
+  resolution: "path-parse@npm:1.0.7"
+  checksum: 49abf3d81115642938a8700ec580da6e830dde670be21893c62f4e10bd7dd4c3742ddc603fe24f898cba7eb0c6bc1777f8d9ac14185d34540c6d4d80cd9cae8a
+  languageName: node
+  linkType: hard
+
 "path-type@npm:^4.0.0":
   version: 4.0.0
   resolution: "path-type@npm:4.0.0"
@@ -4529,6 +4808,15 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"plur@npm:^4.0.0":
+  version: 4.0.0
+  resolution: "plur@npm:4.0.0"
+  dependencies:
+    irregular-plurals: ^3.2.0
+  checksum: fea2e903efca67cc5c7a8952fca3db46ae8d9e9353373b406714977e601a5d3b628bcb043c3ad2126c6ff0e73d8020bf43af30a72dd087eff1ec240eb13b90e1
+  languageName: node
+  linkType: hard
+
 "prelude-ls@npm:~1.1.2":
   version: 1.1.2
   resolution: "prelude-ls@npm:1.1.2"
@@ -4616,6 +4904,13 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"quick-lru@npm:^4.0.1":
+  version: 4.0.1
+  resolution: "quick-lru@npm:4.0.1"
+  checksum: bea46e1abfaa07023e047d3cf1716a06172c4947886c053ede5c50321893711577cb6119360f810cc3ffcd70c4d7db4069c3cee876b358ceff8596e062bd1154
+  languageName: node
+  linkType: hard
+
 "react-is@npm:^17.0.1":
   version: 17.0.1
   resolution: "react-is@npm:17.0.1"
@@ -4623,6 +4918,29 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"read-pkg-up@npm:^7.0.0, read-pkg-up@npm:^7.0.1":
+  version: 7.0.1
+  resolution: "read-pkg-up@npm:7.0.1"
+  dependencies:
+    find-up: ^4.1.0
+    read-pkg: ^5.2.0
+    type-fest: ^0.8.1
+  checksum: e4e93ce70e5905b490ca8f883eb9e48b5d3cebc6cd4527c25a0d8f3ae2903bd4121c5ab9c5a3e217ada0141098eeb661313c86fa008524b089b8ed0b7f165e44
+  languageName: node
+  linkType: hard
+
+"read-pkg@npm:^5.2.0":
+  version: 5.2.0
+  resolution: "read-pkg@npm:5.2.0"
+  dependencies:
+    "@types/normalize-package-data": ^2.4.0
+    normalize-package-data: ^2.5.0
+    parse-json: ^5.0.0
+    type-fest: ^0.6.0
+  checksum: eb696e60528b29aebe10e499ba93f44991908c57d70f2d26f369e46b8b9afc208ef11b4ba64f67630f31df8b6872129e0a8933c8c53b7b4daf0eace536901222
+  languageName: node
+  linkType: hard
+
 "readable-stream@npm:^2.0.6":
   version: 2.3.7
   resolution: "readable-stream@npm:2.3.7"
@@ -4638,6 +4956,16 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+"redent@npm:^3.0.0":
+  version: 3.0.0
+  resolution: "redent@npm:3.0.0"
+  dependencies:
+    indent-string: ^4.0.0
+    strip-indent: ^3.0.0
+  checksum: fa1ef20404a2d399235e83cc80bd55a956642e37dd197b4b612ba7327bf87fa32745aeb4a1634b2bab25467164ab4ed9c15be2c307923dd08b0fe7c52431ae6b
+  languageName: node
+  linkType: hard
+
 "remark-frontmatter@npm:^1.2.0":
   version: 1.3.3
   resolution: "remark-frontmatter@npm:1.3.3"
@@ -4715,6 +5043,19 @@ fsevents@^2.3.2:
   languageName: node
   linkType: hard
 
+resolve@^1.10.0:
+  version: 1.22.0
+  resolution: "resolve@npm:1.22.0"
+  dependencies:
+    is-core-module: ^2.8.1
+    path-parse: ^1.0.7
+    supports-preserve-symlinks-flag: ^1.0.0
+  bin:
+    resolve: bin/resolve
+  checksum: a2d14cc437b3a23996f8c7367eee5c7cf8149c586b07ca2ae00e96581ce59455555a1190be9aa92154785cf9f2042646c200d0e00e0bbd2b8a995a93a0ed3e4e
+  languageName: node
+  linkType: hard
+
 resolve@^1.20.0:
   version: 1.20.0
   resolution: "resolve@npm:1.20.0"
@@ -4734,6 +5075,19 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
+"resolve@patch:resolve@^1.10.0#~builtin<compat/resolve>":
+  version: 1.22.0
+  resolution: "resolve@patch:resolve@npm%3A1.22.0#~builtin<compat/resolve>::version=1.22.0&hash=00b1ff"
+  dependencies:
+    is-core-module: ^2.8.1
+    path-parse: ^1.0.7
+    supports-preserve-symlinks-flag: ^1.0.0
+  bin:
+    resolve: bin/resolve
+  checksum: b63b73ecbb7928e71c30e231f6adc380fca66bd5819a1b1324d3dcae573c726d9923df06eef3ac50be52b1dcea67272f3b6f12ba2e87ec8a9d3ebdf8454103bb
+  languageName: node
+  linkType: hard
+
 "resolve@patch:resolve@^1.20.0#~builtin<compat/resolve>":
   version: 1.20.0
   resolution: "resolve@patch:resolve@npm%3A1.20.0#~builtin<compat/resolve>::version=1.20.0&hash=00b1ff"
@@ -4808,6 +5162,15 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
+"semver@npm:2 || 3 || 4 || 5, semver@npm:^5.4.1":
+  version: 5.7.1
+  resolution: "semver@npm:5.7.1"
+  bin:
+    semver: ./bin/semver
+  checksum: 57fd0acfd0bac382ee87cd52cd0aaa5af086a7dc8d60379dfe65fea491fb2489b6016400813930ecd61fd0952dae75c115287a1b16c234b1550887117744dfaf
+  languageName: node
+  linkType: hard
+
 "semver@npm:7.x, semver@npm:^7.3.2":
   version: 7.3.4
   resolution: "semver@npm:7.3.4"
@@ -4819,15 +5182,6 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
-"semver@npm:^5.4.1":
-  version: 5.7.1
-  resolution: "semver@npm:5.7.1"
-  bin:
-    semver: ./bin/semver
-  checksum: 57fd0acfd0bac382ee87cd52cd0aaa5af086a7dc8d60379dfe65fea491fb2489b6016400813930ecd61fd0952dae75c115287a1b16c234b1550887117744dfaf
-  languageName: node
-  linkType: hard
-
 "semver@npm:^6.0.0, semver@npm:^6.3.0":
   version: 6.3.0
   resolution: "semver@npm:6.3.0"
@@ -4837,7 +5191,7 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
-"semver@npm:^7.3.5":
+"semver@npm:^7.3.4, semver@npm:^7.3.5":
   version: 7.3.5
   resolution: "semver@npm:7.3.5"
   dependencies:
@@ -4951,6 +5305,40 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
+"spdx-correct@npm:^3.0.0":
+  version: 3.1.1
+  resolution: "spdx-correct@npm:3.1.1"
+  dependencies:
+    spdx-expression-parse: ^3.0.0
+    spdx-license-ids: ^3.0.0
+  checksum: 77ce438344a34f9930feffa61be0eddcda5b55fc592906ef75621d4b52c07400a97084d8701557b13f7d2aae0cb64f808431f469e566ef3fe0a3a131dcb775a6
+  languageName: node
+  linkType: hard
+
+"spdx-exceptions@npm:^2.1.0":
+  version: 2.3.0
+  resolution: "spdx-exceptions@npm:2.3.0"
+  checksum: cb69a26fa3b46305637123cd37c85f75610e8c477b6476fa7354eb67c08128d159f1d36715f19be6f9daf4b680337deb8c65acdcae7f2608ba51931540687ac0
+  languageName: node
+  linkType: hard
+
+"spdx-expression-parse@npm:^3.0.0":
+  version: 3.0.1
+  resolution: "spdx-expression-parse@npm:3.0.1"
+  dependencies:
+    spdx-exceptions: ^2.1.0
+    spdx-license-ids: ^3.0.0
+  checksum: a1c6e104a2cbada7a593eaa9f430bd5e148ef5290d4c0409899855ce8b1c39652bcc88a725259491a82601159d6dc790bedefc9016c7472f7de8de7361f8ccde
+  languageName: node
+  linkType: hard
+
+"spdx-license-ids@npm:^3.0.0":
+  version: 3.0.11
+  resolution: "spdx-license-ids@npm:3.0.11"
+  checksum: 1da1acb090257773e60b022094050e810ae9fec874dc1461f65dc0400cd42dd830ab2df6e64fb49c2db3dce386dd0362110780e1b154db7c0bb413488836aaeb
+  languageName: node
+  linkType: hard
+
 "sprintf-js@npm:~1.0.2":
   version: 1.0.3
   resolution: "sprintf-js@npm:1.0.3"
@@ -5082,6 +5470,15 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
+"strip-indent@npm:^3.0.0":
+  version: 3.0.0
+  resolution: "strip-indent@npm:3.0.0"
+  dependencies:
+    min-indent: ^1.0.0
+  checksum: 18f045d57d9d0d90cd16f72b2313d6364fd2cb4bf85b9f593523ad431c8720011a4d5f08b6591c9d580f446e78855c5334a30fb91aa1560f5d9f95ed1b4a0530
+  languageName: node
+  linkType: hard
+
 "strip-json-comments@npm:^3.1.1":
   version: 3.1.1
   resolution: "strip-json-comments@npm:3.1.1"
@@ -5135,6 +5532,13 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
+"supports-preserve-symlinks-flag@npm:^1.0.0":
+  version: 1.0.0
+  resolution: "supports-preserve-symlinks-flag@npm:1.0.0"
+  checksum: 53b1e247e68e05db7b3808b99b892bd36fb096e6fba213a06da7fab22045e97597db425c724f2bbd6c99a3c295e1e73f3e4de78592289f38431049e1277ca0ae
+  languageName: node
+  linkType: hard
+
 "symbol-tree@npm:^3.2.4":
   version: 3.2.4
   resolution: "symbol-tree@npm:3.2.4"
@@ -5241,6 +5645,13 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
+"trim-newlines@npm:^3.0.0":
+  version: 3.0.1
+  resolution: "trim-newlines@npm:3.0.1"
+  checksum: b530f3fadf78e570cf3c761fb74fef655beff6b0f84b29209bac6c9622db75ad1417f4a7b5d54c96605dcd72734ad44526fef9f396807b90839449eb543c6206
+  languageName: node
+  linkType: hard
+
 "trim-trailing-lines@npm:^1.0.0":
   version: 1.1.3
   resolution: "trim-trailing-lines@npm:1.1.3"
@@ -5334,6 +5745,22 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
+"tsd@npm:^0.19.1":
+  version: 0.19.1
+  resolution: "tsd@npm:0.19.1"
+  dependencies:
+    "@tsd/typescript": ~4.5.2
+    eslint-formatter-pretty: ^4.1.0
+    globby: ^11.0.1
+    meow: ^9.0.0
+    path-exists: ^4.0.0
+    read-pkg-up: ^7.0.0
+  bin:
+    tsd: dist/cli.js
+  checksum: be8531da502c5de9b99a013b15d1fed854141e5b893c9e4075a8b440a5210bacbba389a63638b583c144b259fbcc97160021b106cb32d32e6187a37649a8667e
+  languageName: node
+  linkType: hard
+
 "type-check@npm:~0.3.2":
   version: 0.3.2
   resolution: "type-check@npm:0.3.2"
@@ -5357,6 +5784,27 @@ resolve@^1.3.2:
   languageName: node
   linkType: hard
 
+"type-fest@npm:^0.18.0":
+  version: 0.18.1
+  resolution: "type-fest@npm:0.18.1"
+  checksum: e96dcee18abe50ec82dab6cbc4751b3a82046da54c52e3b2d035b3c519732c0b3dd7a2fa9df24efd1a38d953d8d4813c50985f215f1957ee5e4f26b0fe0da395
+  languageName: node
+  linkType: hard
+
+"type-fest@npm:^0.6.0":
+  version: 0.6.0
+  resolution: "type-fest@npm:0.6.0"
+  checksum: b2188e6e4b21557f6e92960ec496d28a51d68658018cba8b597bd3ef757721d1db309f120ae987abeeda874511d14b776157ff809f23c6d1ce8f83b9b2b7d60f
+  languageName: node
+  linkType: hard
+
+"type-fest@npm:^0.8.1":
+  version: 0.8.1
+  resolution: "type-fest@npm:0.8.1"
+  checksum: d61c4b2eba24009033ae4500d7d818a94fd6d1b481a8111612ee141400d5f1db46f199c014766b9fa9b31a6a7374d96fc748c6d688a78a3ce5a33123839becb7
+  languageName: node
+  linkType: hard
+
 "typed-emitter@npm:^1.3.1":
   version: 1.4.0
   resolution: "typed-emitter@npm:1.4.0"
@@ -5529,6 +5977,16 @@ typescript@4.6.2:
   languageName: node
   linkType: hard
 
+"validate-npm-package-license@npm:^3.0.1":
+  version: 3.0.4
+  resolution: "validate-npm-package-license@npm:3.0.4"
+  dependencies:
+    spdx-correct: ^3.0.0
+    spdx-expression-parse: ^3.0.0
+  checksum: 35703ac889d419cf2aceef63daeadbe4e77227c39ab6287eeb6c1b36a746b364f50ba22e88591f5d017bc54685d8137bc2d328d0a896e4d3fd22093c0f32a9ad
+  languageName: node
+  linkType: hard
+
 "vfile-location@npm:^2.0.0":
   version: 2.0.6
   resolution: "vfile-location@npm:2.0.6"
@@ -5764,6 +6222,13 @@ typescript@4.6.2:
   languageName: node
   linkType: hard
 
+"yargs-parser@npm:^20.2.3":
+  version: 20.2.9
+  resolution: "yargs-parser@npm:20.2.9"
+  checksum: 8bb69015f2b0ff9e17b2c8e6bfe224ab463dd00ca211eece72a4cd8a906224d2703fb8a326d36fdd0e68701e201b2a60ed7cf81ce0fd9b3799f9fe7745977ae3
+  languageName: node
+  linkType: hard
+
 "yargs@npm:^16.2.0":
   version: 16.2.0
   resolution: "yargs@npm:16.2.0"

From 95074fcda636674b3a749349dbb3cf8f8a5a56f1 Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 15:01:41 +0000
Subject: [PATCH 02/10] test: expand type tests

---
 .github/workflows/ci.yaml |  2 +-
 test-d/command.test-d.ts  | 17 +++++++++++++++++
 test-d/program.test-d.ts  | 20 ++++++++++++++++++++
 3 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index bf178f95..89b7af0a 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -21,8 +21,8 @@ jobs:
         with:
           node-version: ${{ matrix.node }}
       - run: yarn install
-      - run: yarn test
       - run: yarn build
+      - run: yarn test
 
   coverage:
     needs: test
diff --git a/test-d/command.test-d.ts b/test-d/command.test-d.ts
index 1caf995c..89df1ad3 100644
--- a/test-d/command.test-d.ts
+++ b/test-d/command.test-d.ts
@@ -4,3 +4,20 @@ import { Command, command } from '../src/command'
 const cmd = command()
 
 expectType<Command>(cmd)
+
+// Chainable methods
+expectType<Command>(cmd.description('foo'))
+expectType<Command>(cmd.hidden())
+expectType<Command>(cmd.add(cmd))
+expectType<Command>(cmd.default())
+expectType<Command>(cmd.action(undefined))
+
+// Argument types
+cmd.argument('foo').action((args) => {
+  expectType<{ foo: string }>(args)
+})
+
+// Option types
+cmd.option('foo').action((args) => {
+  expectType<{ foo: unknown }>(args)
+})
diff --git a/test-d/program.test-d.ts b/test-d/program.test-d.ts
index 333ddb47..ca2532ae 100644
--- a/test-d/program.test-d.ts
+++ b/test-d/program.test-d.ts
@@ -1,6 +1,26 @@
 import { expectType } from 'tsd'
+import { command } from '../src/command'
 import { Program, program } from '../src/program'
+import { Repl } from '../src/repl'
 
 const app = program()
 
 expectType<Program>(app)
+
+// Chainable methods
+expectType<Program>(app.description('foo'))
+expectType<Program>(app.prompt('foo'))
+expectType<Program>(app.add(command()))
+expectType<Program>(app.default(command()))
+expectType<Program>(app.on('run', undefined))
+
+// Run methods
+expectType<Promise<unknown>>(app.run('foo'))
+expectType<Promise<unknown>>(app.run(['foo', 'bar']))
+expectType<Promise<unknown>>(app.run())
+expectType<Repl>(app.repl())
+expectType<Repl | Promise<unknown>>(app.runOrRepl())
+
+// Getters
+expectType<boolean>(app.isRepl())
+expectType<boolean>(app.isRepl())

From 38695cf98831203c1aeebb0d6829db9f087da891 Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 15:37:06 +0000
Subject: [PATCH 03/10] test: add failing test

---
 .vscode/settings.json    |  2 +-
 package.json             |  2 +-
 src/baseArg.ts           | 19 +++++++++++++++++--
 test-d/command.test-d.ts | 16 ++++++++++++++++
 tsconfig.json            |  2 +-
 5 files changed, 36 insertions(+), 5 deletions(-)

diff --git a/.vscode/settings.json b/.vscode/settings.json
index 910a2a5f..25fa6215 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -1,3 +1,3 @@
 {
-    "typescript.tsdk": "node_modules\\typescript\\lib"
+  "typescript.tsdk": "node_modules/typescript/lib"
 }
diff --git a/package.json b/package.json
index 69e87376..f39e23ea 100644
--- a/package.json
+++ b/package.json
@@ -25,7 +25,7 @@
   "types": "lib/index.d.ts",
   "scripts": {
     "prepublishOnly": "yarn build",
-    "build": "tsc",
+    "build": "tsc --rootDir src",
     "watch": "tsc --watch",
     "lint": "prettier --write \"src/**/*\"",
     "test": "tsd && jest",
diff --git a/src/baseArg.ts b/src/baseArg.ts
index 7f467bf4..aaa9341f 100644
--- a/src/baseArg.ts
+++ b/src/baseArg.ts
@@ -8,7 +8,7 @@ export interface BaseArgOptions {
 
 export type InferArgType<O extends Options | PositionalOptions, F = unknown> =
   /**
-   * Add support for numeric variadic arguments
+   * Numeric variadic arguments
    */
   O extends {
     variadic: true
@@ -16,12 +16,27 @@ export type InferArgType<O extends Options | PositionalOptions, F = unknown> =
   }
     ? Array<number>
     : /**
-     * Add support for string variadic arguments
+     * String variadic arguments
      */
     O extends {
         variadic: true
       }
     ? Array<string>
+    : /**
+     * Numeric optional argument
+     */
+    O extends {
+        optional: true
+        type: 'number'
+      }
+    ? number | undefined
+    : /**
+     * String optional argument
+     */
+    O extends {
+        optional: true
+      }
+    ? string | undefined
     : /**
      * Choices with array type
      */ O extends { choices: ReadonlyArray<infer C>; type: 'array' }
diff --git a/test-d/command.test-d.ts b/test-d/command.test-d.ts
index 89df1ad3..84213951 100644
--- a/test-d/command.test-d.ts
+++ b/test-d/command.test-d.ts
@@ -14,8 +14,24 @@ expectType<Command>(cmd.action(undefined))
 
 // Argument types
 cmd.argument('foo').action((args) => {
+  // Argument without options
   expectType<{ foo: string }>(args)
 })
+cmd.argument('foo', { default: 'bar' }).action((args) => {
+  // Argument with default
+  expectType<{ foo: string }>(args)
+})
+cmd.argument('foo', { optional: true }).action((args) => {
+  // Optional argument
+  expectType<{ foo: string }>(args)
+})
+cmd
+  .argument('foo', {
+    type: 'number',
+  })
+  .action((args) => {
+    expectType<{ foo: number }>(args)
+  })
 
 // Option types
 cmd.option('foo').action((args) => {
diff --git a/tsconfig.json b/tsconfig.json
index cab0f582..5e31cf76 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,5 +1,5 @@
 {
-  "include": ["./src"],
+  "include": ["src", "tests", "test-d"],
   "compilerOptions": {
     "target": "es2017",
     "module": "commonjs",

From c63dcd31891b9d662deeff3e0db0b67bedeac783 Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 15:37:40 +0000
Subject: [PATCH 04/10] test: add failing tests

---
 package.json             |  2 +-
 test-d/command.test-d.ts | 76 +++++++++++++++++++++++++++++++++-------
 test-d/program.test-d.ts |  2 +-
 tsconfig.build.json      |  9 +++++
 tsconfig.json            | 11 +++---
 5 files changed, 80 insertions(+), 20 deletions(-)
 create mode 100644 tsconfig.build.json

diff --git a/package.json b/package.json
index f39e23ea..927694f7 100644
--- a/package.json
+++ b/package.json
@@ -25,7 +25,7 @@
   "types": "lib/index.d.ts",
   "scripts": {
     "prepublishOnly": "yarn build",
-    "build": "tsc --rootDir src",
+    "build": "tsc --project tsconfig.build.json",
     "watch": "tsc --watch",
     "lint": "prettier --write \"src/**/*\"",
     "test": "tsd && jest",
diff --git a/test-d/command.test-d.ts b/test-d/command.test-d.ts
index 84213951..13350483 100644
--- a/test-d/command.test-d.ts
+++ b/test-d/command.test-d.ts
@@ -10,30 +10,80 @@ expectType<Command>(cmd.description('foo'))
 expectType<Command>(cmd.hidden())
 expectType<Command>(cmd.add(cmd))
 expectType<Command>(cmd.default())
-expectType<Command>(cmd.action(undefined))
+expectType<Command>(cmd.action(() => {}))
 
-// Argument types
+// String argument types
 cmd.argument('foo').action((args) => {
-  // Argument without options
+  // No options
   expectType<{ foo: string }>(args)
 })
 cmd.argument('foo', { default: 'bar' }).action((args) => {
-  // Argument with default
+  // With default
   expectType<{ foo: string }>(args)
 })
 cmd.argument('foo', { optional: true }).action((args) => {
-  // Optional argument
-  expectType<{ foo: string }>(args)
+  // Optional
+  expectType<{ foo: string | undefined }>(args)
+})
+cmd.argument('foo', { optional: true, default: 'bar' }).action((args) => {
+  // Optional with default
+  expectType<{ foo: string | undefined }>(args)
+})
+
+// Numeric argument types
+cmd.argument('foo', { type: 'number' }).action((args) => {
+  // No options
+  expectType<{ foo: number }>(args)
+})
+cmd.argument('foo', { type: 'number', default: 100 }).action((args) => {
+  // With default
+  expectType<{ foo: number }>(args)
+})
+cmd.argument('foo', { default: 100 }).action((args) => {
+  // Inferred from default
+  expectType<{ foo: number }>(args)
+})
+cmd.argument('foo', { type: 'number', optional: true }).action((args) => {
+  // Optional
+  expectType<{ foo: number | undefined }>(args)
 })
 cmd
-  .argument('foo', {
-    type: 'number',
-  })
+  .argument('foo', { type: 'number', optional: true, default: 100 })
   .action((args) => {
-    expectType<{ foo: number }>(args)
+    // Optional with default
+    expectType<{ foo: string | undefined }>(args)
   })
+cmd.argument('foo', { optional: true, default: 100 }).action((args) => {
+  // Optional inferred from default
+  expectType<{ foo: number | undefined }>(args)
+})
 
-// Option types
-cmd.option('foo').action((args) => {
-  expectType<{ foo: unknown }>(args)
+// Boolean argument types
+cmd.argument('foo', { type: 'boolean' }).action((args) => {
+  // No options
+  expectType<{ foo: boolean }>(args)
 })
+cmd.argument('foo', { type: 'boolean', default: false }).action((args) => {
+  // With default
+  expectType<{ foo: boolean }>(args)
+})
+cmd.argument('foo', { default: false }).action((args) => {
+  // Inferred from default
+  expectType<{ foo: boolean }>(args)
+})
+cmd.argument('foo', { type: 'boolean', optional: true }).action((args) => {
+  // Optional
+  expectType<{ foo: boolean | undefined }>(args)
+})
+cmd
+  .argument('foo', { type: 'boolean', optional: true, default: false })
+  .action((args) => {
+    // Optional with default
+    expectType<{ foo: boolean | undefined }>(args)
+  })
+cmd.argument('foo', { optional: true, default: false }).action((args) => {
+  // Optional inferred from default
+  expectType<{ foo: boolean | undefined }>(args)
+})
+
+// @todo: option types
diff --git a/test-d/program.test-d.ts b/test-d/program.test-d.ts
index ca2532ae..7648161f 100644
--- a/test-d/program.test-d.ts
+++ b/test-d/program.test-d.ts
@@ -12,7 +12,7 @@ expectType<Program>(app.description('foo'))
 expectType<Program>(app.prompt('foo'))
 expectType<Program>(app.add(command()))
 expectType<Program>(app.default(command()))
-expectType<Program>(app.on('run', undefined))
+expectType<Program>(app.on('run', () => {}))
 
 // Run methods
 expectType<Promise<unknown>>(app.run('foo'))
diff --git a/tsconfig.build.json b/tsconfig.build.json
new file mode 100644
index 00000000..b9ebe6b1
--- /dev/null
+++ b/tsconfig.build.json
@@ -0,0 +1,9 @@
+{
+  "extends": "tsconfig.json",
+  "include": ["src"],
+  "compilerOptions": {
+    "outDir": "lib",
+    "rootDir": "src",
+    "declaration": true
+  }
+}
diff --git a/tsconfig.json b/tsconfig.json
index 5e31cf76..88dbf549 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,15 +1,16 @@
 {
   "include": ["src", "tests", "test-d"],
   "compilerOptions": {
+    "rootDir": ".",
+    "noEmit": true,
+
     "target": "es2017",
     "module": "commonjs",
     "lib": ["es2017"],
-    "declaration": true,
-    "outDir": "lib",
-    "rootDir": "src",
-    "strict": true,
     "allowSyntheticDefaultImports": true,
+    "moduleResolution": "node",
     "esModuleInterop": true,
-    "moduleResolution": "node"
+
+    "strict": true
   }
 }

From 4043259941cc5bb04d0907a00793a5bf35859dfd Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 16:47:08 +0000
Subject: [PATCH 05/10] fix: types

---
 README.md                |  4 +-
 TODO.md                  | 12 ++++--
 examples/types.ts        | 57 +++++++++++++++++++++++++--
 package.json             |  2 +-
 src/baseArg.ts           | 85 ++++++++++++++++------------------------
 src/command.ts           |  6 ++-
 src/option.ts            |  7 ++--
 test-d/command.test-d.ts | 10 ++---
 tsconfig.build.json      |  4 +-
 tsconfig.json            |  3 +-
 10 files changed, 115 insertions(+), 75 deletions(-)

diff --git a/README.md b/README.md
index 2bcc2b0a..4d59601c 100644
--- a/README.md
+++ b/README.md
@@ -737,9 +737,7 @@ Optionally deploy to GitHub, S3, etc. using your preferred CD method if needed.
 
 ## Todo
 
-- [ ] Better code coverage
-- [ ] Consider resolving ambiguity in _prompt_ param/method
-- [ ] Async autocomplete method for arg values
+See [TODO.md](TODO.md)
 
 ## Contributing
 
diff --git a/TODO.md b/TODO.md
index 4523b4c3..672d757a 100644
--- a/TODO.md
+++ b/TODO.md
@@ -1,5 +1,9 @@
 ### TODOs
-| Filename | line # | TODO
-|:------|:------:|:------
-| [src/prompter.ts](src/prompter.ts#L16) | 16 | Wait for upstream change to import types from enquirer
-| [src/prompter.ts](src/prompter.ts#L77) | 77 | ignoring type error here, probably need another type
+| Filename | line # | TODO |
+|:------|:------:|:------|
+| [src/baseArg.ts](src/baseArg.ts#L88) | 88 | See if we can add this to autocompleter |
+| [src/command.ts](src/command.ts#L278) | 278 | coerce all types and remove coerce option from baseArg |
+| [src/command.ts](src/command.ts#L293) | 293 | Upgrade to native async handlers in yarn 17 |
+| [src/prompter.ts](src/prompter.ts#L16) | 16 | Wait for upstream change to import types from enquirer |
+| [src/prompter.ts](src/prompter.ts#L77) | 77 | ignoring type error here, probably need another type |
+| [test-d/command.test-d.ts](test-d/command.test-d.ts#L89) | 89 | option types |
diff --git a/examples/types.ts b/examples/types.ts
index a4ec8c5a..297cad45 100644
--- a/examples/types.ts
+++ b/examples/types.ts
@@ -1,4 +1,4 @@
-import { program, command } from '../src'
+import { command, program } from '../src'
 
 /**
  * Keep in mind that argument/option types are not validated at runtime.
@@ -7,8 +7,57 @@ import { program, command } from '../src'
  */
 
 const string = command('string')
-  .argument('arg', { description: 'Required string argument' })
-  .option('opt', { description: 'Optional string option', type: 'string' })
+  .argument('arg1', { description: 'Required string argument' })
+  .argument('arg2', { optional: true, description: 'Optional string argument' })
+  .argument('arg3', { variadic: true, description: 'Variadic string argument' })
+  .option('opt1', { type: 'string', description: 'String option' })
+  .option('opt2', {
+    default: 'foo',
+    description: 'String option with default',
+  })
+  .action((args) => {
+    console.log('Args are', args)
+  })
+
+const number = command('number')
+  .argument('arg1', { type: 'number', description: 'Required number argument' })
+  .argument('arg2', {
+    type: 'number',
+    optional: true,
+    description: 'Optional number argument',
+  })
+  .argument('arg3', {
+    type: 'number',
+    variadic: true,
+    description: 'Variadic number argument',
+  })
+  .option('opt1', { type: 'number', description: 'number option' })
+  .option('opt2', { default: 100, description: 'Number option with default' })
+  .action((args) => {
+    console.log('Args are', args)
+  })
+
+const boolean = command('boolean')
+  .argument('arg1', {
+    type: 'boolean',
+    description: 'Required boolean argument',
+  })
+  .argument('arg2', {
+    type: 'boolean',
+    optional: true,
+    description: 'Optional boolean argument',
+  })
+  .argument('arg3', {
+    type: 'boolean',
+    variadic: true,
+    description: 'Variadic boolean argument',
+  })
+  .option('opt1', { type: 'boolean', description: 'number option' })
+  .option('opt2', {
+    type: 'boolean',
+    default: false,
+    description: 'Number option with default',
+  })
   .action((args) => {
     console.log('Args are', args)
   })
@@ -41,6 +90,8 @@ const defaultValues = command('default')
 const app = program()
   .description('All argument and option types')
   .add(string)
+  .add(number)
+  .add(boolean)
   .add(choices)
   .add(defaultValues)
 
diff --git a/package.json b/package.json
index 927694f7..55f9e7f9 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
     "test": "tsd && jest",
     "start": "ts-node",
     "doc:toc": "doctoc README.md",
-    "doc:todos": "leasot --exit-nicely --reporter markdown \"src/**/*.ts\" > TODO.md"
+    "doc:todos": "leasot --exit-nicely --reporter markdown \"{src,test-d,tests}/**/*.ts\" > TODO.md"
   },
   "author": "",
   "license": "MIT",
diff --git a/src/baseArg.ts b/src/baseArg.ts
index aaa9341f..658f7cb1 100644
--- a/src/baseArg.ts
+++ b/src/baseArg.ts
@@ -6,58 +6,40 @@ export interface BaseArgOptions {
   prompt?: true | string
 }
 
+// prettier-ignore
 export type InferArgType<O extends Options | PositionalOptions, F = unknown> =
-  /**
-   * Numeric variadic arguments
-   */
-  O extends {
-    variadic: true
-    type: 'number'
-  }
-    ? Array<number>
-    : /**
-     * String variadic arguments
-     */
-    O extends {
-        variadic: true
-      }
-    ? Array<string>
-    : /**
-     * Numeric optional argument
-     */
-    O extends {
-        optional: true
-        type: 'number'
-      }
-    ? number | undefined
-    : /**
-     * String optional argument
-     */
-    O extends {
-        optional: true
-      }
-    ? string | undefined
-    : /**
-     * Choices with array type
-     */ O extends { choices: ReadonlyArray<infer C>; type: 'array' }
-    ? C[]
-    : /**
-     * Choices with array default
-     */ O extends {
-        choices: ReadonlyArray<infer C>
-        default: ReadonlyArray<string>
-      }
-    ? C[]
-    : /**
-     * Prefer choices over default
-     */ O extends { choices: ReadonlyArray<infer C> }
-    ? C
-    : /**
-     * Allow fallback type
-     */
-    unknown extends InferredOptionType<O>
-    ? F
-    : InferredOptionType<O>
+  // Default number
+  O extends { default: number } ? number :  
+  // Optional number
+  O extends { type: 'number', optional: true } ? number | undefined :  
+  // Variadic number
+  O extends { type: 'number', variadic: true } ? Array<number> :  
+  // Number
+  O extends { type: 'number' } ? number :  
+  // Default boolean
+  O extends { default: boolean } ? boolean :  
+  // Optional boolean
+  O extends { type: 'boolean', optional: true } ? boolean | undefined :  
+  // Variadic boolean
+  O extends { type: 'boolean', variadic: true } ? Array<boolean> :  
+  // Boolean
+  O extends { type: 'boolean' } ? boolean :  
+  // Default string
+  O extends { default: string } ? string :  
+  // Optional string
+  O extends { optional: true } ? string | undefined :  
+  // Variadic string
+  O extends { variadic: true } ? Array<string> :  
+  // Choices with array type
+  O extends { choices: ReadonlyArray<infer C>; type: 'array' } ? C[] :
+  // Choices with array default
+  O extends { choices: ReadonlyArray<infer C>, default: ReadonlyArray<string> } ? C[] :
+  // Prefer choices over default
+  O extends { choices: ReadonlyArray<infer C> } ? C :
+  // Allow fallback type
+  unknown extends InferredOptionType<O> ? F :
+  // yargs type
+  InferredOptionType<O>
 
 export class BaseArg {
   protected name: string
@@ -102,6 +84,7 @@ export class BaseArg {
 
   /**
    * Get possible values, is specified.
+   * @todo See if we can add this to autocompleter
    */
   getChoices() {
     return this.options.choices
diff --git a/src/command.ts b/src/command.ts
index b266aabc..65fbd0c5 100644
--- a/src/command.ts
+++ b/src/command.ts
@@ -92,7 +92,7 @@ export class Command<T = {}> {
   ) {
     this.add(new Argument(name, options))
 
-    return (this as unknown) as Command<
+    return this as unknown as Command<
       T & { [key in K]: InferArgType<O, string> }
     >
   }
@@ -107,7 +107,7 @@ export class Command<T = {}> {
   ) {
     this.add(new Option(name, options))
 
-    return (this as unknown) as Command<T & { [key in K]: InferArgType<O> }>
+    return this as unknown as Command<T & { [key in K]: InferArgType<O> }>
   }
 
   /**
@@ -275,6 +275,7 @@ export class Command<T = {}> {
       let promise = prompterInstance.prompt()
 
       promise = promise.then((args) => {
+        // @todo coerce all types and remove coerce option from baseArg
         if (this.handler) {
           return this.handler(args, commandRunner)
         }
@@ -289,6 +290,7 @@ export class Command<T = {}> {
 
       // Save promise chain on argv instance, so we can access it in parse
       // callback.
+      // @todo Upgrade to native async handlers in yarn 17
       argv.__promise = promise
 
       return promise
diff --git a/src/option.ts b/src/option.ts
index 016721da..06070e97 100644
--- a/src/option.ts
+++ b/src/option.ts
@@ -1,5 +1,5 @@
-import { Options as BaseOptions, Argv } from 'yargs'
-import { BaseArgOptions, BaseArg } from './baseArg'
+import { Argv, Options as BaseOptions } from 'yargs'
+import { BaseArg, BaseArgOptions } from './baseArg'
 
 // We ignore some not-so-common use cases from the type to make using this
 // library easier. They could still be used at runtime but won't be documented
@@ -14,6 +14,7 @@ type IgnoreOptions =
   | 'defaultDescription'
   | 'demand'
   | 'demandOption'
+  | 'deprecate'
   | 'desc'
   | 'describe'
   | 'global'
@@ -28,7 +29,7 @@ type IgnoreOptions =
   | 'requiresArg'
   | 'skipValidation'
   | 'string'
-// | 'implies'
+  | 'implies'
 
 export interface OptionOptions
   extends Omit<BaseOptions, IgnoreOptions>,
diff --git a/test-d/command.test-d.ts b/test-d/command.test-d.ts
index 13350483..e5d23cf5 100644
--- a/test-d/command.test-d.ts
+++ b/test-d/command.test-d.ts
@@ -27,7 +27,7 @@ cmd.argument('foo', { optional: true }).action((args) => {
 })
 cmd.argument('foo', { optional: true, default: 'bar' }).action((args) => {
   // Optional with default
-  expectType<{ foo: string | undefined }>(args)
+  expectType<{ foo: string }>(args)
 })
 
 // Numeric argument types
@@ -51,11 +51,11 @@ cmd
   .argument('foo', { type: 'number', optional: true, default: 100 })
   .action((args) => {
     // Optional with default
-    expectType<{ foo: string | undefined }>(args)
+    expectType<{ foo: number }>(args)
   })
 cmd.argument('foo', { optional: true, default: 100 }).action((args) => {
   // Optional inferred from default
-  expectType<{ foo: number | undefined }>(args)
+  expectType<{ foo: number }>(args)
 })
 
 // Boolean argument types
@@ -79,11 +79,11 @@ cmd
   .argument('foo', { type: 'boolean', optional: true, default: false })
   .action((args) => {
     // Optional with default
-    expectType<{ foo: boolean | undefined }>(args)
+    expectType<{ foo: boolean }>(args)
   })
 cmd.argument('foo', { optional: true, default: false }).action((args) => {
   // Optional inferred from default
-  expectType<{ foo: boolean | undefined }>(args)
+  expectType<{ foo: boolean }>(args)
 })
 
 // @todo: option types
diff --git a/tsconfig.build.json b/tsconfig.build.json
index b9ebe6b1..1278bfb3 100644
--- a/tsconfig.build.json
+++ b/tsconfig.build.json
@@ -1,9 +1,9 @@
 {
-  "extends": "tsconfig.json",
+  "extends": "./tsconfig.json",
   "include": ["src"],
   "compilerOptions": {
     "outDir": "lib",
     "rootDir": "src",
-    "declaration": true
+    "noEmit": false
   }
 }
diff --git a/tsconfig.json b/tsconfig.json
index 88dbf549..df4715a4 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,8 +1,9 @@
 {
-  "include": ["src", "tests", "test-d"],
+  "include": ["src", "tests", "test-d", "examples"],
   "compilerOptions": {
     "rootDir": ".",
     "noEmit": true,
+    "declaration": true,
 
     "target": "es2017",
     "module": "commonjs",

From 49d2c9e59d7f88a3f29bd0c087d641a04940249e Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 16:53:32 +0000
Subject: [PATCH 06/10] build: fix cc

---
 .github/workflows/ci.yaml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 89b7af0a..5537dadf 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -23,6 +23,9 @@ jobs:
       - run: yarn install
       - run: yarn build
       - run: yarn test
+      - uses: actions/upload-artifact@v3
+        with:
+          path: lib
 
   coverage:
     needs: test
@@ -30,6 +33,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - run: yarn install
+      - uses: actions/download-artifact@v3
       - uses: paambaati/codeclimate-action@v3.0.0
         env:
           CC_TEST_REPORTER_ID: e1a2f8ecd90c13810c302d9cdfb4a26a5b79666e899c4f353e558416c168da0d

From fc2c92447d610e968593a2a0fde69c52de8c0894 Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 16:57:24 +0000
Subject: [PATCH 07/10] build: cache node_modules

---
 .github/workflows/ci.yaml      | 8 ++++++++
 .github/workflows/release.yaml | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 5537dadf..8c961a36 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -20,6 +20,14 @@ jobs:
       - uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node }}
+      - id: yarn-cache-dir-path
+        run: echo "::set-output name=dir::$(yarn config get cacheFolder)"
+      - uses: actions/cache@v3
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
       - run: yarn install
       - run: yarn build
       - run: yarn test
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 3d7a4de4..cebe6b49 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 16
       - run: yarn install
       - run: npx semantic-release
         env:

From c1e723b864b9cb3bbc326b8ccb5c087ef6534a11 Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 16:58:15 +0000
Subject: [PATCH 08/10] build: cache more

---
 .github/workflows/ci.yaml      | 8 ++++++++
 .github/workflows/release.yaml | 9 +++++++--
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 8c961a36..749b1b98 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -40,6 +40,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
+      - id: yarn-cache-dir-path
+        run: echo "::set-output name=dir::$(yarn config get cacheFolder)"
+      - uses: actions/cache@v3
+        with:
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
       - run: yarn install
       - uses: actions/download-artifact@v3
       - uses: paambaati/codeclimate-action@v3.0.0
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index cebe6b49..2dee7eef 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -11,9 +11,14 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - uses: actions/setup-node@v3
+      - id: yarn-cache-dir-path
+        run: echo "::set-output name=dir::$(yarn config get cacheFolder)"
+      - uses: actions/cache@v3
         with:
-          node-version: 16
+          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
+          key: ${{ runner.os }}-yarn-${{ hashFiles('**/yarn.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-yarn-
       - run: yarn install
       - run: npx semantic-release
         env:

From d0e6ba6a7054f8c271b24efd40ecf858358a1015 Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 17:03:27 +0000
Subject: [PATCH 09/10] build: fix artifacts (?)

---
 .github/workflows/ci.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 749b1b98..87257344 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -33,6 +33,7 @@ jobs:
       - run: yarn test
       - uses: actions/upload-artifact@v3
         with:
+          name: lib
           path: lib
 
   coverage:
@@ -50,6 +51,8 @@ jobs:
             ${{ runner.os }}-yarn-
       - run: yarn install
       - uses: actions/download-artifact@v3
+        with:
+          name: lib
       - uses: paambaati/codeclimate-action@v3.0.0
         env:
           CC_TEST_REPORTER_ID: e1a2f8ecd90c13810c302d9cdfb4a26a5b79666e899c4f353e558416c168da0d

From 43f0c53598cf4bbc6cc7fc57332f998d631bad16 Mon Sep 17 00:00:00 2001
From: Joram van den Boezem <joram@vandenboezem.nl>
Date: Tue, 22 Mar 2022 17:05:40 +0000
Subject: [PATCH 10/10] build: fix artifact path (?)

---
 .github/workflows/ci.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 87257344..a2b4ff2a 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -53,6 +53,7 @@ jobs:
       - uses: actions/download-artifact@v3
         with:
           name: lib
+          path: lib
       - uses: paambaati/codeclimate-action@v3.0.0
         env:
           CC_TEST_REPORTER_ID: e1a2f8ecd90c13810c302d9cdfb4a26a5b79666e899c4f353e558416c168da0d