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

Fixes #1527

Author: joaovieira

CHANGELOG.md

@@ -6,6 +6,9 @@ This change log adheres to standards from [Keep a CHANGELOG](http://keepachangel
 
 ## [Unreleased]
 
+### Added
+- [`import/default`]: support default export in TSExportAssignment ([#1528], thanks [@joaovieira])
+
 ### Fixed
 - [`group-exports`]: Flow type export awareness ([#1702], thanks [@ernestostifano])
 - [`order`]: Recognize pathGroup config for first group ([#1719], [#1724], thanks [@forivall], [@xpl])
@@ -697,6 +700,7 @@ for info on changes for earlier releases.
 [#1560]: https://github.com/benmosher/eslint-plugin-import/pull/1560
 [#1551]: https://github.com/benmosher/eslint-plugin-import/pull/1551
 [#1542]: https://github.com/benmosher/eslint-plugin-import/pull/1542
+[#1528]: https://github.com/benmosher/eslint-plugin-import/pull/1528
 [#1526]: https://github.com/benmosher/eslint-plugin-import/pull/1526
 [#1521]: https://github.com/benmosher/eslint-plugin-import/pull/1521
 [#1519]: https://github.com/benmosher/eslint-plugin-import/pull/1519

src/ExportMap.js

@@ -530,30 +530,50 @@ ExportMap.parse = function (path, content, context) {
 
     // This doesn't declare anything, but changes what's being exported.
     if (n.type === 'TSExportAssignment') {
-      const moduleDecls = ast.body.filter((bodyNode) =>
-        bodyNode.type === 'TSModuleDeclaration' && bodyNode.id.name === n.expression.name
+      const exportedName = n.expression.name
+      const declTypes = [
+        'VariableDeclaration',
+        'ClassDeclaration',
+        'TSDeclareFunction',
+        'TSEnumDeclaration',
+        'TSTypeAliasDeclaration',
+        'TSInterfaceDeclaration',
+        'TSAbstractClassDeclaration',
+        'TSModuleDeclaration',
+      ]
+      const exportedDecls = ast.body.filter(({ type, id, declarations }) => 
+        declTypes.includes(type) && 
+        (id && id.name === exportedName || declarations.find(d => d.id.name === exportedName))
       )
-      moduleDecls.forEach((moduleDecl) => {
-        if (moduleDecl && moduleDecl.body && moduleDecl.body.body) {
-          moduleDecl.body.body.forEach((moduleBlockNode) => {
+      if (exportedDecls.length === 0) {
+        // Export is not referencing any local declaration, must be re-exporting
+        m.namespace.set('default', captureDoc(source, docStyleParsers, n))
+        return
+      }
+      exportedDecls.forEach((decl) => {
+        if (decl.type === 'TSModuleDeclaration' && decl && decl.body && decl.body.body) {
+          decl.body.body.forEach((moduleBlockNode) => {
             // Export-assignment exports all members in the namespace, explicitly exported or not.
-            const exportedDecl = moduleBlockNode.type === 'ExportNamedDeclaration' ?
+            const namespaceDecl = moduleBlockNode.type === 'ExportNamedDeclaration' ?
               moduleBlockNode.declaration :
               moduleBlockNode
 
-            if (exportedDecl.type === 'VariableDeclaration') {
-              exportedDecl.declarations.forEach((decl) =>
-                recursivePatternCapture(decl.id,(id) => m.namespace.set(
+            if (namespaceDecl.type === 'VariableDeclaration') {
+              namespaceDecl.declarations.forEach((d) =>
+                recursivePatternCapture(d.id, (id) => m.namespace.set(
                   id.name,
-                  captureDoc(source, docStyleParsers, decl, exportedDecl, moduleBlockNode))
+                  captureDoc(source, docStyleParsers, decl, namespaceDecl, moduleBlockNode))
                 )
               )
             } else {
               m.namespace.set(
-                exportedDecl.id.name,
+                namespaceDecl.id.name,
                 captureDoc(source, docStyleParsers, moduleBlockNode))
             }
           })
+        } else {
+          // Export as default
+          m.namespace.set('default', captureDoc(source, docStyleParsers, decl))
         }
       })
     }

tests/files/typescript-default.ts

@@ -0,0 +1 @@
+export default function foobar() {};

tests/files/typescript-export-assign-default-reexport.ts

@@ -0,0 +1,2 @@
+import { getFoo } from './typescript';
+export = getFoo;

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

@@ -0,0 +1,3 @@
+export = foobar;
+
+declare const foobar: number;

tests/files/typescript-export-assign-mixed.d.ts

@@ -0,0 +1,11 @@
+export = foobar;
+
+declare function foobar(): void;
+declare namespace foobar {
+  type MyType = string
+  enum MyEnum {
+    Foo,
+    Bar,
+    Baz
+  }
+}

tests/files/typescript-export-assign-merged.d.ts renamed to tests/files/typescript-export-assign-namespace-merged.d.ts

@@ -1,4 +1,4 @@
-import { test, SYNTAX_CASES } from '../utils'
+import { test, SYNTAX_CASES, getTSParsers } from '../utils'
 import { RuleTester } from 'eslint'
 
 import { CASE_SENSITIVE_FS } from 'eslint-module-utils/resolve'
@@ -152,3 +152,56 @@ if (!CASE_SENSITIVE_FS) {
     ],
   })
 }
+
+context('TypeScript', function () {
+  getTSParsers().forEach((parser) => {
+      ruleTester.run(`default`, rule, {
+        valid: [
+          test({
+            code: `import foobar from "./typescript-default"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+          }),
+          test({
+            code: `import foobar from "./typescript-export-assign-default"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+          }),
+          test({
+            code: `import foobar from "./typescript-export-assign-mixed"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+          }),
+          test({
+            code: `import foobar from "./typescript-export-assign-default-reexport"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+          }),
+        ],
+
+        invalid: [
+          test({
+            code: `import foobar from "./typescript"`,
+            parser: parser,
+            settings: {
+              'import/parsers': { [parser]: ['.ts'] },
+              'import/resolver': { 'eslint-import-resolver-typescript': true },
+            },
+            errors: ['No default export found in imported module "./typescript".'],
+          }),
+        ],
+      })
+    })
+})

tests/files/typescript-export-assign.d.ts renamed to tests/files/typescript-export-assign-namespace.d.ts

@@ -285,7 +285,12 @@ ruleTester.run('named (export *)', rule, {
 
 context('TypeScript', function () {
   getTSParsers().forEach((parser) => {
-    ['typescript', 'typescript-declare', 'typescript-export-assign', 'typescript-export-assign-merged'].forEach((source) => {
+    [
+      'typescript', 
+      'typescript-declare', 
+      'typescript-export-assign-namespace', 
+      'typescript-export-assign-namespace-merged',
+    ].forEach((source) => {
       ruleTester.run(`named`, rule, {
         valid: [
           test({