fix(eslint-plugin): [no-duplicate-imports] distinguish member, default (

#2637)

packages/eslint-plugin/src/rules/no-duplicate-imports.ts

@@ -35,7 +35,8 @@ export default util.createRule<Options, MessageIds>({
   create(context, [option]) {
     const rules = baseRule.create(context);
     const includeExports = option.includeExports;
-    const typeImports = new Set();
+    const typeMemberImports = new Set();
+    const typeDefaultImports = new Set();
     const typeExports = new Set();
 
     function report(
@@ -62,16 +63,32 @@ export default util.createRule<Options, MessageIds>({
       );
     }
 
+    function isAllMemberImport(node: TSESTree.ImportDeclaration): boolean {
+      return node.specifiers.every(
+        specifier => specifier.type === AST_NODE_TYPES.ImportSpecifier,
+      );
+    }
+
     function checkTypeImport(node: TSESTree.ImportDeclaration): void {
       if (isStringLiteral(node.source)) {
         const value = node.source.value;
-        if (typeImports.has(value)) {
+        const isMemberImport = isAllMemberImport(node);
+        if (
+          isMemberImport
+            ? typeMemberImports.has(value)
+            : typeDefaultImports.has(value)
+        ) {
           report('importType', node, value);
         }
+
         if (includeExports && typeExports.has(value)) {
           report('importTypeAs', node, value);
         }
-        typeImports.add(value);
+        if (isMemberImport) {
+          typeMemberImports.add(value);
+        } else {
+          typeDefaultImports.add(value);
+        }
       }
     }
 
@@ -83,7 +100,7 @@ export default util.createRule<Options, MessageIds>({
         if (typeExports.has(value)) {
           report('exportType', node, value);
         }
-        if (typeImports.has(value)) {
+        if (typeMemberImports.has(value) || typeDefaultImports.has(value)) {
           report('exportTypeAs', node, value);
         }
         typeExports.add(value);

packages/eslint-plugin/tests/rules/no-duplicate-imports.test.ts

@@ -5,14 +5,32 @@ const ruleTester = new RuleTester({
   parser: '@typescript-eslint/parser',
 });
 
-ruleTester.run('no-dupe-class-members', rule, {
+ruleTester.run('no-duplicate-imports', rule, {
   valid: [
     {
       code: "import type foo from 'foo';",
     },
     {
       code: "import type { foo } from 'foo';",
     },
+    {
+      code: `
+        import type { foo } from 'foo';
+        import type Bar from 'foo';
+      `,
+    },
+    {
+      code: `
+        import type Foo from 'foo';
+        import type { bar } from 'foo';
+      `,
+    },
+    {
+      code: `
+        import type Foo from 'foo';
+        import type { bar as Bar } from 'foo';
+      `,
+    },
     {
       code: `
         import foo from 'foo';
@@ -69,6 +87,14 @@ ruleTester.run('no-dupe-class-members', rule, {
       `,
       options: [{ includeExports: true }],
     },
+    {
+      code: `
+        import type Foo from 'foo';
+        import type { bar } from 'foo';
+        export type { bar };
+      `,
+      options: [{ includeExports: true }],
+    },
   ],
   invalid: [
     {
@@ -116,6 +142,15 @@ ruleTester.run('no-dupe-class-members', rule, {
       options: [{ includeExports: true }],
       errors: [{ messageId: 'exportTypeAs' }],
     },
+    {
+      code: `
+        import type Foo from 'foo';
+        import type { bar } from 'foo';
+        export type { bar } from 'foo';
+      `,
+      options: [{ includeExports: true }],
+      errors: [{ messageId: 'exportTypeAs' }],
+    },
     {
       code: `
         export type * as foo from 'foo';