Add import type and export type support to TypeScript

packages/babel-generator/test/fixtures/typescript/export-declaration-type/input.js

@@ -0,0 +1,2 @@
+export interface A {}
+export type B = string;

packages/babel-generator/test/fixtures/typescript/export-declaration-type/output.js

@@ -0,0 +1,2 @@
+export interface A {}
+export type B = string;

packages/babel-generator/test/fixtures/typescript/export-type/input.js

@@ -0,0 +1,3 @@
+type A = 2;
+export type { A };
+export type { B } from "./mod";

packages/babel-generator/test/fixtures/typescript/export-type/output.js

@@ -0,0 +1,3 @@
+type A = 2;
+export type { A };
+export type { B } from "./mod";

packages/babel-generator/test/fixtures/typescript/import-type/input.js

@@ -0,0 +1,3 @@
+import type T from './mod';
+import type { A, B } from './mod';
+import type * as Types from './mod';

packages/babel-generator/test/fixtures/typescript/import-type/output.js

@@ -0,0 +1,3 @@
+import type T from './mod';
+import type { A, B } from './mod';
+import type * as Types from './mod';

packages/babel-parser/src/plugins/typescript/index.js

@@ -1839,7 +1839,30 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       if (this.match(tt.name) && this.lookahead().type === tt.eq) {
         return this.tsParseImportEqualsDeclaration(node);
       }
-      return super.parseImport(node);
+
+      if (this.eatContextual("type")) {
+        node.importKind = "type";
+      } else {
+        node.importKind = "value";
+      }
+
+      const importNode = super.parseImport(node);
+      /*:: invariant(importNode.type !== "TSImportEqualsDeclaration") */
+
+      // `import type` can only be used on imports with named imports or with a
+      // default import - but not both
+      if (
+        importNode.importKind === "type" &&
+        importNode.specifiers.length > 1 &&
+        importNode.specifiers[0].type === "ImportDefaultSpecifier"
+      ) {
+        this.raise(
+          importNode.start,
+          "A type-only import can specify a default import or named bindings, but not both.",
+        );
+      }
+
+      return importNode;
     }
 
     parseExport(node: N.Node): N.AnyExport {
@@ -1862,6 +1885,13 @@ export default (superClass: Class<Parser>): Class<Parser> =>
         this.semicolon();
         return this.finishNode(decl, "TSNamespaceExportDeclaration");
       } else {
+        if (this.isContextual("type") && this.lookahead().type === tt.braceL) {
+          this.next();
+          node.exportKind = "type";
+        } else {
+          node.exportKind = "value";
+        }
+
         return super.parseExport(node);
       }
     }
@@ -2097,6 +2127,14 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       if (!declaration) {
         declaration = super.parseExportDeclaration(node);
       }
+      if (
+        declaration &&
+        (declaration.type === "TSInterfaceDeclaration" ||
+          declaration.type === "TSTypeAliasDeclaration" ||
+          isDeclare)
+      ) {
+        node.exportKind = "type";
+      }
 
       if (declaration && isDeclare) {
         // Reset location to include `declare` in range

packages/babel-parser/test/fixtures/experimental/export-extensions/default-type-with-typescript/input.js

@@ -0,0 +1 @@
+export type from 'test';

packages/babel-parser/test/fixtures/experimental/export-extensions/default-type-with-typescript/options.json

@@ -0,0 +1,5 @@
+{
+  "plugins": ["exportDefaultFrom", "typescript"],
+  "sourceType": "module",
+  "throws": "Unexpected token, expected \"=\" (1:17)"
+}

packages/babel-parser/test/fixtures/experimental/export-extensions/export-with-ts/output.json

@@ -43,6 +43,7 @@
             "column": 26
           }
         },
+        "exportKind": "value",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -110,6 +111,7 @@
             "column": 29
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -176,6 +178,7 @@
             "column": 16
           }
         },
+        "exportKind": "value",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -226,6 +229,7 @@
             "column": 21
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -291,6 +295,7 @@
             "column": 18
           }
         },
+        "exportKind": "value",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -356,6 +361,7 @@
             "column": 21
           }
         },
+        "exportKind": "value",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -421,6 +427,7 @@
             "column": 27
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {

packages/babel-parser/test/fixtures/typescript/class/abstract-false-positive/output.json

@@ -43,6 +43,7 @@
             "column": 24
           }
         },
+        "exportKind": "value",
         "declaration": {
           "type": "Identifier",
           "start": 78,

packages/babel-parser/test/fixtures/typescript/class/abstract/output.json

@@ -144,6 +144,7 @@
             "column": 27
           }
         },
+        "exportKind": "value",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -229,6 +230,7 @@
             "column": 33
           }
         },
+        "exportKind": "value",
         "declaration": {
           "type": "ClassDeclaration",
           "start": 148,
@@ -296,6 +298,7 @@
             "column": 36
           }
         },
+        "exportKind": "value",
         "declaration": {
           "type": "ClassDeclaration",
           "start": 182,

packages/babel-parser/test/fixtures/typescript/enum/export-const/output.json

@@ -43,6 +43,7 @@
             "column": 22
           }
         },
+        "exportKind": "value",
         "specifiers": [],
         "source": null,
         "declaration": {

packages/babel-parser/test/fixtures/typescript/enum/export-declare-const/output.json

@@ -43,6 +43,7 @@
             "column": 30
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {

packages/babel-parser/test/fixtures/typescript/enum/export/output.json

@@ -43,6 +43,7 @@
             "column": 16
           }
         },
+        "exportKind": "value",
         "specifiers": [],
         "source": null,
         "declaration": {

packages/babel-parser/test/fixtures/typescript/export/declare/output.json

@@ -43,6 +43,7 @@
             "column": 31
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -142,6 +143,7 @@
             "column": 34
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -225,6 +227,7 @@
             "column": 25
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -292,6 +295,7 @@
             "column": 29
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -358,6 +362,7 @@
             "column": 31
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -423,6 +428,7 @@
             "column": 26
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -489,6 +495,7 @@
             "column": 29
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {
@@ -555,6 +562,7 @@
             "column": 26
           }
         },
+        "exportKind": "type",
         "specifiers": [],
         "source": null,
         "declaration": {

packages/babel-parser/test/fixtures/typescript/export/export-type-declaration/input.ts

@@ -0,0 +1,4 @@
+export type A = 2;
+export interface B {}
+export declare function a(): string;
+export declare var b: string;