From 40d1e6785412892515c0a1800aae8a32494bde9f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fredrik=20H=C3=B6glund?= <fredrik.hoglund@gmail.com>
Date: Mon, 13 Apr 2020 23:20:59 +0200
Subject: [PATCH] [Fix] `no-unused-modules`: Count re-export as usage when used
 in combination with import

---
 CHANGELOG.md                                     |  3 +++
 src/rules/no-unused-modules.js                   |  8 +++++++-
 tests/files/no-unused-modules/import-export-1.js |  2 ++
 tests/files/no-unused-modules/import-export-2.js |  2 ++
 tests/src/rules/no-unused-modules.js             | 11 +++++++++++
 5 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 tests/files/no-unused-modules/import-export-1.js
 create mode 100644 tests/files/no-unused-modules/import-export-2.js

diff --git a/CHANGELOG.md b/CHANGELOG.md
index be86fcd50..5525a6f14 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 ### Fixed
 - [`group-exports`]: Flow type export awareness ([#1702], thanks [@ernestostifano])
 - [`order`]: Recognize pathGroup config for first group ([#1719], [#1724], thanks [@forivall], [@xpl])
+- [`no-unused-modules`]: Fix re-export not counting as usage when used in combination with import ([#1722], thanks [@Ephem])
 
 ### Changed
 - TypeScript config: Disable [`named`][] ([#1726], thanks [@astorije])
@@ -669,6 +670,7 @@ for info on changes for earlier releases.
 
 [#1726]: https://github.com/benmosher/eslint-plugin-import/issues/1726
 [#1724]: https://github.com/benmosher/eslint-plugin-import/issues/1724
+[#1722]: https://github.com/benmosher/eslint-plugin-import/issues/1722
 [#1719]: https://github.com/benmosher/eslint-plugin-import/issues/1719
 [#1702]: https://github.com/benmosher/eslint-plugin-import/issues/1702
 [#1666]: https://github.com/benmosher/eslint-plugin-import/pull/1666
@@ -1138,3 +1140,4 @@ for info on changes for earlier releases.
 [@forivall]: https://github.com/forivall
 [@xpl]: https://github.com/xpl
 [@astorije]: https://github.com/astorije
+[@Ephem]: https://github.com/Ephem
diff --git a/src/rules/no-unused-modules.js b/src/rules/no-unused-modules.js
index 9468dc87d..60416d21c 100644
--- a/src/rules/no-unused-modules.js
+++ b/src/rules/no-unused-modules.js
@@ -196,7 +196,13 @@ const prepareImportsAndExports = (srcFiles, context) => {
         if (isNodeModule(key)) {
           return
         }
-        imports.set(key, value.importedSpecifiers)
+        let localImport = imports.get(key)
+        if (typeof localImport !== 'undefined') {
+          localImport = new Set([...localImport, ...value.importedSpecifiers])
+        } else {
+          localImport = value.importedSpecifiers
+        }
+        imports.set(key, localImport)
       })
       importList.set(file, imports)
 
diff --git a/tests/files/no-unused-modules/import-export-1.js b/tests/files/no-unused-modules/import-export-1.js
new file mode 100644
index 000000000..218c3cff7
--- /dev/null
+++ b/tests/files/no-unused-modules/import-export-1.js
@@ -0,0 +1,2 @@
+export const a = 5;
+export const b = 'b';
diff --git a/tests/files/no-unused-modules/import-export-2.js b/tests/files/no-unused-modules/import-export-2.js
new file mode 100644
index 000000000..9cfb2747b
--- /dev/null
+++ b/tests/files/no-unused-modules/import-export-2.js
@@ -0,0 +1,2 @@
+import { a } from './import-export-1';
+export { b } from './import-export-1';
diff --git a/tests/src/rules/no-unused-modules.js b/tests/src/rules/no-unused-modules.js
index d1a7f62fd..702406316 100644
--- a/tests/src/rules/no-unused-modules.js
+++ b/tests/src/rules/no-unused-modules.js
@@ -427,6 +427,17 @@ ruleTester.run('no-unused-modules', rule, {
   ],
 })
 
+// Test that import and export in the same file both counts as usage
+ruleTester.run('no-unused-modules', rule, {
+  valid: [
+    test({ options: unusedExportsOptions,
+          code: `export const a = 5;export const b = 't1'`,
+          filename: testFilePath('./no-unused-modules/import-export-1.js'),
+        }),
+  ],
+  invalid: [],
+})
+
 describe('test behaviour for new file', () => {
   before(() => {
     fs.writeFileSync(testFilePath('./no-unused-modules/file-added-0.js'), '', {encoding: 'utf8'})