build(client-tree): exports with ESM as primary

common/build/build-common/src/cjs/package.json

@@ -0,0 +1,3 @@
+{
+	"type": "commonjs"
+}

common/build/build-common/src/esm/package.json

@@ -0,0 +1,3 @@
+{
+	"type": "module"
+}

fluidBuild.config.cjs

@@ -150,6 +150,8 @@ module.exports = {
 	// `flub check policy` config. It applies to the whole repo.
 	policy: {
 		exclusions: [
+			"common/build/build-common/src/cjs/package.json",
+			"common/build/build-common/src/esm/package.json",
 			"docs/layouts/",
 			"docs/themes/thxvscode/assets/",
 			"docs/themes/thxvscode/layouts/",
@@ -181,6 +183,9 @@ module.exports = {
 				"^packages/utils/.*/package.json",
 				"^packages/loader/container-loader/package.json",
 			],
+			"fluid-build-tasks-tsc": [
+				"packages/dds/tree/package.json", // Builds CommonJS with custom tsconfig
+			],
 			"html-copyright-file-header": [
 				// Tests generate HTML "snapshot" artifacts
 				"tools/api-markdown-documenter/src/test/snapshots/.*",
@@ -238,6 +243,7 @@ module.exports = {
 				"^tools/getkeys",
 			],
 			"npm-package-json-esm": [
+				"packages/dds/tree/package.json", // Policy is incorrect about "module" in package.json
 				// These are ESM-only packages and use tsc to build the ESM output. The policy handler doesn't understand this
 				// case.
 				"packages/dds/migration-shim/package.json",

packages/dds/tree/api-extractor-cjs.json

@@ -0,0 +1,10 @@
+{
+	"$schema": "https://developer.microsoft.com/json-schemas/api-extractor/v7/api-extractor.schema.json",
+	"extends": "../../../common/build/build-common/api-extractor-base.cjs.primary.json",
+	"compiler": {
+		"tsconfigFilePath": "<projectFolder>/tsconfig.cjs.json"
+	},
+	"apiReport": {
+		"enabled": false
+	}
+}

packages/dds/tree/api-extractor-esm.json

@@ -0,0 +1,14 @@
+{
+	"$schema": "https://developer.microsoft.com/json-schemas/api-extractor/v7/api-extractor.schema.json",
+	"extends": "../../../common/build/build-common/api-extractor-base.esm.primary.json",
+	"compiler": {
+		"overrideTsconfig": {
+			"$schema": "http://json.schemastore.org/tsconfig",
+			"extends": "./tsconfig.esnext.json",
+			"compilerOptions": {
+				"module": "esnext",
+				"moduleResolution": "Bundler"
+			}
+		}
+	}
+}

packages/dds/tree/api-extractor-lint.json

@@ -1,4 +1,4 @@
 {
 	"$schema": "https://developer.microsoft.com/json-schemas/api-extractor/v7/api-extractor.schema.json",
-	"extends": "../../../common/build/build-common/api-extractor-lint.json"
+	"extends": "../../../common/build/build-common/api-extractor-lint.esm.primary.json"
 }

packages/dds/tree/api-extractor.json

@@ -1,4 +1,15 @@
 {
 	"$schema": "https://developer.microsoft.com/json-schemas/api-extractor/v7/api-extractor.schema.json",
-	"extends": "../../../common/build/build-common/api-extractor-base.json"
+	"extends": "../../../common/build/build-common/api-extractor-base.json",
+	"mainEntryPointFilePath": "./lib/index.d.ts",
+	"compiler": {
+		"overrideTsconfig": {
+			"$schema": "http://json.schemastore.org/tsconfig",
+			"extends": "./tsconfig.esnext.json",
+			"compilerOptions": {
+				"module": "esnext",
+				"moduleResolution": "Bundler"
+			}
+		}
+	}
 }

packages/dds/tree/package.json

@@ -11,17 +11,42 @@
 	"license": "MIT",
 	"author": "Microsoft and contributors",
 	"sideEffects": false,
+	"type": "module",
+	"exports": {
+		".": {
+			"import": {
+				"types": "./lib/tree-public.d.ts",
+				"default": "./lib/index.js"
+			},
+			"require": {
+				"types": "./dist/tree-public.d.ts",
+				"default": "./dist/index.js"
+			}
+		},
+		"./internal": {
+			"import": {
+				"types": "./lib/index.d.ts",
+				"default": "./lib/index.js"
+			},
+			"require": {
+				"types": "./dist/index.d.ts",
+				"default": "./dist/index.js"
+			}
+		}
+	},
 	"main": "dist/index.js",
-	"module": "lib/index.js",
 	"types": "dist/index.d.ts",
 	"scripts": {
+		"api": "fluid-build . --task api",
+		"api-extractor:commonjs": "api-extractor run --config ./api-extractor-cjs.json",
+		"api-extractor:esnext": "api-extractor run --local --config ./api-extractor-esm.json",
 		"bench": "mocha --timeout 999999 --perfMode --parentProcess --fgrep @Benchmark --reporter @fluid-tools/benchmark/dist/MochaReporter.js",
 		"bench:profile": "mocha --v8-prof --v8-logfile=profile.log --v8-no-logfile-per-isolate --timeout 999999 --perfMode --fgrep @Benchmark --reporter @fluid-tools/benchmark/dist/MochaReporter.js && node --prof-process profile.log > profile.txt && rimraf profile.log && echo See results in profile.txt",
 		"build": "fluid-build . --task build",
 		"build:commonjs": "fluid-build . --task commonjs",
 		"build:compile": "fluid-build . --task compile",
 		"build:docs": "api-extractor run --local",
-		"build:esnext": "tsc --project ./tsconfig.esnext.json",
+		"build:esnext": "tsc --project ./tsconfig.esnext.json && copyfiles -f ../../../common/build/build-common/src/esm/package.json ./lib",
 		"build:genver": "gen-version",
 		"build:test": "tsc --project ./src/test/tsconfig.json",
 		"check:are-the-types-wrong": "attw --pack . --entrypoints .",
@@ -46,7 +71,7 @@
 		"test:snapshots:regen": "npm run test:mocha -- --snapshot",
 		"test:stress": "cross-env FUZZ_TEST_COUNT=20 FUZZ_STRESS_RUN=true mocha --ignore \"dist/test/memory/**/*\" --recursive \"dist/test/**/*.spec.js\" -r @fluidframework/mocha-test-setup",
 		"ts2esm": "ts2esm ./tsconfig.json ./src/test/tsconfig.json",
-		"tsc": "tsc",
+		"tsc": "tsc --project ./tsconfig.cjs.json && copyfiles -f ../../../common/build/build-common/src/cjs/package.json ./dist",
 		"typetests:gen": "fluid-type-test-generator",
 		"typetests:prepare": "flub typetests --dir . --reset --previous --normalize"
 	},
@@ -112,6 +137,7 @@
 		"ajv": "^8.12.0",
 		"ajv-formats": "^2.1.1",
 		"c8": "^8.0.1",
+		"copyfiles": "^2.4.1",
 		"cross-env": "^7.0.3",
 		"dependency-cruiser": "^14.1.0",
 		"diff": "^3.5.0",
@@ -127,6 +153,22 @@
 		"ts2esm": "^1.1.0",
 		"typescript": "~5.1.6"
 	},
+	"fluidBuild": {
+		"tasks": {
+			"build:docs": {
+				"dependsOn": [
+					"build:esnext"
+				],
+				"script": false
+			},
+			"check:release-tags": [
+				"build:esnext"
+			],
+			"ci:build:docs": [
+				"build:esnext"
+			]
+		}
+	},
 	"typeValidation": {
 		"disabled": true,
 		"broken": {}

packages/dds/tree/tsconfig.base.json

@@ -0,0 +1,17 @@
+{
+	"extends": "@fluidframework/build-common/ts-common-config.json",
+	"exclude": ["src/test/**/*"],
+	"compilerOptions": {
+		"rootDir": "./src",
+		"outDir": "./error-override-outdir-in-main-tsconfig",
+		"noImplicitAny": true,
+		"composite": true,
+		"preserveConstEnums": true,
+		// Allow unused locals.
+		// This is needed for type assertions using the TypeCheck library.
+		// Linter is used to enforce "_" prefix for unused locals to prevent accidentally having unused locals.
+		"noUnusedLocals": false,
+		"noImplicitOverride": true,
+	},
+	"include": ["src/**/*"],
+}

packages/dds/tree/tsconfig.cjs.json

@@ -0,0 +1,17 @@
+{
+	"extends": "./tsconfig.base.json",
+	"compilerOptions": {
+		"outDir": "./dist",
+		// Ideally there would be no CommonJS transpilation and wrappers would exist around
+		// ESM modules as needed. Until there is such support also transpile to CommonJS.
+		// Next preference is to use Node16 for module and moduleResolution with package.json
+		// "type": "commonjs". However "type": "module" is required to activate full ESM Mode
+		// for the ESM build.
+		// If solution like tsc-multi adds support for package.json type override then this
+		// can be Node16 with a "type": "commonjs" package.json override.
+		// Underlying reason for the complexity here is that base tools wish to avoid the dual
+		// package hazard of ESM and CommonJS in the same package. "tsc-multi" is a workaround.
+		"module": "CommonJS",
+		"moduleResolution": "Node10",
+	},
+}

packages/dds/tree/tsconfig.esnext.json

@@ -1,7 +1,10 @@
 {
-	"extends": "./tsconfig.json",
+	"extends": "./tsconfig.base.json",
 	"compilerOptions": {
 		"outDir": "./lib",
-		"module": "esnext",
+		// Node16 and ESNext is effectively the same for transpile so long as package.json has
+		// "type": "module", which is required to activate full ESM Mode within tsc.
+		"module": "Node16",
+		"moduleResolution": "Node16",
 	},
 }

packages/dds/tree/tsconfig.json

@@ -1,17 +1,3 @@
 {
-	"extends": "@fluidframework/build-common/ts-common-config.json",
-	"exclude": ["src/test/**/*"],
-	"compilerOptions": {
-		"rootDir": "./src",
-		"outDir": "./dist",
-		"noImplicitAny": true,
-		"composite": true,
-		"preserveConstEnums": true,
-		// Allow unused locals.
-		// This is needed for type assertions using the TypeCheck library.
-		// Linter is used to enforce "_" prefix for unused locals to prevent accidentally having unused locals.
-		"noUnusedLocals": false,
-		"noImplicitOverride": true,
-	},
-	"include": ["src/**/*"],
+	"extends": "./tsconfig.esnext.json",
 }