[New] import/default: support default export in TSExportAssignment

Author: Maxim-Mazurok

CHANGELOG.md

@@ -10,6 +10,7 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 - [`import/default`]: support default export in TSExportAssignment ([#1528], thanks [@joaovieira])
 - [`no-cycle`]: add `ignoreExternal` option ([#1681], thanks [@sveyret])
 - [`order`]: Add support for TypeScript's "import equals"-expressions ([#1785], thanks [@manuth])
+- [`import/default`]: support default export in TSExportAssignment ([#1689], thanks [@Maxim-Mazurok])
 
 ### Fixed
 - [`group-exports`]: Flow type export awareness ([#1702], thanks [@ernestostifano])
@@ -705,6 +706,7 @@ for info on changes for earlier releases.
 [#1702]: https://github.com/benmosher/eslint-plugin-import/issues/1702
 [#1691]: https://github.com/benmosher/eslint-plugin-import/pull/1691
 [#1690]: https://github.com/benmosher/eslint-plugin-import/pull/1690
+[#1689]: https://github.com/benmosher/eslint-plugin-import/pull/1689
 [#1681]: https://github.com/benmosher/eslint-plugin-import/pull/1681
 [#1676]: https://github.com/benmosher/eslint-plugin-import/pull/1676
 [#1666]: https://github.com/benmosher/eslint-plugin-import/pull/1666
@@ -1189,3 +1191,4 @@ for info on changes for earlier releases.
 [@barbogast]: https://github.com/barbogast
 [@adamborowski]: https://github.com/adamborowski
 [@adjerbetian]: https://github.com/adjerbetian
+[@Maxim-Mazurok]: https://github.com/Maxim-Mazurok

package.json

@@ -108,7 +108,8 @@
     "minimatch": "^3.0.4",
     "object.values": "^1.1.0",
     "read-pkg-up": "^2.0.0",
-    "resolve": "^1.12.0"
+    "resolve": "^1.12.0",
+    "tsconfig-paths": "^3.9.0"
   },
   "nyc": {
     "require": [

src/ExportMap.js

@@ -13,6 +13,12 @@ import isIgnored, { hasValidExtension } from 'eslint-module-utils/ignore'
 import { hashObject } from 'eslint-module-utils/hash'
 import * as unambiguous from 'eslint-module-utils/unambiguous'
 
+import { tsConfigLoader } from 'tsconfig-paths/lib/tsconfig-loader'
+
+import includes from 'array-includes'
+
+import {parseConfigFileTextToJson} from 'typescript'
+
 const log = debug('eslint-plugin-import:ExportMap')
 
 const exportCache = new Map()
@@ -445,8 +451,23 @@ ExportMap.parse = function (path, content, context) {
 
   const source = makeSourceCode(content, ast)
 
-  ast.body.forEach(function (n) {
+  function isEsModuleInterop() {
+    const tsConfigInfo = tsConfigLoader({
+      cwd: context.parserOptions && context.parserOptions.tsconfigRootDir || process.cwd(),
+      getEnv: (key) => process.env[key],
+    })
+    try {
+      if (tsConfigInfo.tsConfigPath !== undefined) {
+        const jsonText = fs.readFileSync(tsConfigInfo.tsConfigPath).toString()
+        const tsConfig = parseConfigFileTextToJson(tsConfigInfo.tsConfigPath, jsonText).config
+        return tsConfig.compilerOptions.esModuleInterop
+      }
+    } catch (e) {
+      return false
+    }
+  }
 
+  ast.body.forEach(function (n) {
     if (n.type === 'ExportDefaultDeclaration') {
       const exportMeta = captureDoc(source, docStyleParsers, n)
       if (n.declaration.type === 'Identifier') {
@@ -528,9 +549,14 @@ ExportMap.parse = function (path, content, context) {
       })
     }
 
+    const isEsModuleInteropTrue = isEsModuleInterop()
+
+    const exports = ['TSExportAssignment']
+    isEsModuleInteropTrue && exports.push('TSNamespaceExportDeclaration')
+
     // This doesn't declare anything, but changes what's being exported.
-    if (n.type === 'TSExportAssignment') {
-      const exportedName = n.expression.name
+    if (includes(exports, n.type)) {
+      const exportedName = n.expression && n.expression.name || n.id.name
       const declTypes = [
         'VariableDeclaration',
         'ClassDeclaration',
@@ -541,18 +567,17 @@ ExportMap.parse = function (path, content, context) {
         'TSAbstractClassDeclaration',
         'TSModuleDeclaration',
       ]
-      const exportedDecls = ast.body.filter(({ type, id, declarations }) => 
-        declTypes.includes(type) && 
-        (
-          (id && id.name === exportedName) ||
-          (declarations && declarations.find(d => d.id.name === exportedName))
-        )
-      )
+      const exportedDecls = ast.body.filter(({ type, id, declarations }) => includes(declTypes, type) && (
+        (id && id.name === exportedName) || (declarations && declarations.find((d) => d.id.name === exportedName))
+      ))
       if (exportedDecls.length === 0) {
         // Export is not referencing any local declaration, must be re-exporting
         m.namespace.set('default', captureDoc(source, docStyleParsers, n))
         return
       }
+      if (isEsModuleInteropTrue) {
+        m.namespace.set('default', {})
+      }
       exportedDecls.forEach((decl) => {
         if (decl.type === 'TSModuleDeclaration') {
           if (decl.body && decl.body.type === 'TSModuleDeclaration') {

tests/files/typescript-export-as-default-namespace/index.d.ts

@@ -0,0 +1,3 @@
+export as namespace Foo
+
+export function bar(): void

tests/files/typescript-export-as-default-namespace/tsconfig.json

@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "esModuleInterop": true
+    }
+}

tests/files/typescript-export-assign-default-namespace/index.d.ts

@@ -0,0 +1,3 @@
+export = FooBar;
+
+declare namespace FooBar {}

tests/files/typescript-export-assign-default-namespace/tsconfig.json

@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "esModuleInterop": true
+    }
+}

tests/src/rules/default.js

@@ -1,3 +1,4 @@
+import path from 'path'
 import { test, SYNTAX_CASES, getTSParsers } from '../utils'
 import { RuleTester } from 'eslint'
 
@@ -189,6 +190,28 @@ context('TypeScript', function () {
               'import/resolver': { 'eslint-import-resolver-typescript': true },
             },
           }),
+          test({
+            code: `import React from "./typescript-export-assign-default-namespace"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+            parserOptions: {
+              tsconfigRootDir: path.resolve(__dirname, '../../files/typescript-export-assign-default-namespace/'),
+            },
+          }),
+          test({
+            code: `import Foo from "./typescript-export-as-default-namespace"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+            parserOptions: {
+              tsconfigRootDir: path.resolve(__dirname, '../../files/typescript-export-as-default-namespace/'),
+            },
+          }),
         ],
 
         invalid: [
@@ -201,6 +224,24 @@ context('TypeScript', function () {
             },
             errors: ['No default export found in imported module "./typescript".'],
           }),
+          test({
+            code: `import React from "./typescript-export-assign-default-namespace"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+            errors: ['No default export found in imported module "./typescript-export-assign-default-namespace".'],
+          }),
+          test({
+            code: `import FooBar from "./typescript-export-as-default-namespace"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+            errors: ['No default export found in imported module "./typescript-export-as-default-namespace".'],
+          }),
         ],
       })
     })