feat(typescript-estree): support 3.8 import/export type (#1697)

packages/shared-fixtures/fixtures/typescript/basics/export-type-as.src.ts

@@ -0,0 +1 @@
+export type { A as B };

packages/shared-fixtures/fixtures/typescript/basics/export-type-from-as.src.ts

@@ -0,0 +1 @@
+export type { B as C } from './a';

packages/shared-fixtures/fixtures/typescript/basics/export-type-from.src.ts

@@ -0,0 +1 @@
+export type { foo } from 'bar';

packages/shared-fixtures/fixtures/typescript/basics/export-type-star-from.src.ts

@@ -0,0 +1 @@
+export type * from 'bar';

packages/shared-fixtures/fixtures/typescript/basics/export-type.src.ts

@@ -0,0 +1 @@
+export type { foo };

packages/shared-fixtures/fixtures/typescript/basics/import-type-default.src.ts

@@ -0,0 +1 @@
+import type foo from 'bar';

packages/shared-fixtures/fixtures/typescript/basics/import-type-empty.src.ts

@@ -0,0 +1,2 @@
+// this should be treated as a normal import statement
+import type from './foo';

packages/shared-fixtures/fixtures/typescript/basics/import-type-error.src.ts

@@ -0,0 +1 @@
+import type foo, { bar } from 'bar';

packages/shared-fixtures/fixtures/typescript/basics/import-type-named-as.src.ts

@@ -0,0 +1 @@
+import type { foo as bar } from 'baz';

packages/shared-fixtures/fixtures/typescript/basics/import-type-named.src.ts

@@ -0,0 +1 @@
+import type { foo, bar } from 'baz';

packages/shared-fixtures/fixtures/typescript/basics/import-type-star-as-ns.src.ts

@@ -0,0 +1 @@
+import type * as foo from './bar';

packages/typescript-estree/src/convert.ts

@@ -172,11 +172,15 @@ export class Converter {
           range: [exportKeyword.getStart(this.ast), result.range[1]],
         });
       } else {
+        const isType =
+          result.type === AST_NODE_TYPES.TSInterfaceDeclaration ||
+          result.type === AST_NODE_TYPES.TSTypeAliasDeclaration;
         return this.createNode<TSESTree.ExportNamedDeclaration>(node, {
           type: AST_NODE_TYPES.ExportNamedDeclaration,
           declaration: result,
           specifiers: [],
           source: null,
+          exportKind: isType ? 'type' : 'value',
           range: [exportKeyword.getStart(this.ast), result.range[1]],
         });
       }
@@ -1529,9 +1533,14 @@ export class Converter {
           type: AST_NODE_TYPES.ImportDeclaration,
           source: this.convertChild(node.moduleSpecifier),
           specifiers: [],
+          importKind: 'value',
         });
 
         if (node.importClause) {
+          if (node.importClause.isTypeOnly) {
+            result.importKind = 'type';
+          }
+
           if (node.importClause.name) {
             result.specifiers.push(this.convertChild(node.importClause));
           }
@@ -1587,12 +1596,14 @@ export class Converter {
             specifiers: node.exportClause.elements.map(el =>
               this.convertChild(el),
             ),
+            exportKind: node.isTypeOnly ? 'type' : 'value',
             declaration: null,
           });
         } else {
           return this.createNode<TSESTree.ExportAllDeclaration>(node, {
             type: AST_NODE_TYPES.ExportAllDeclaration,
             source: this.convertChild(node.moduleSpecifier),
+            exportKind: node.isTypeOnly ? 'type' : 'value',
           });
         }
 

packages/typescript-estree/src/ts-estree/ts-estree.ts

@@ -868,6 +868,7 @@ export interface EmptyStatement extends BaseNode {
 export interface ExportAllDeclaration extends BaseNode {
   type: AST_NODE_TYPES.ExportAllDeclaration;
   source: Expression | null;
+  exportKind: 'type' | 'value';
 }
 
 export interface ExportDefaultDeclaration extends BaseNode {
@@ -880,6 +881,7 @@ export interface ExportNamedDeclaration extends BaseNode {
   declaration: ExportDeclaration | null;
   specifiers: ExportSpecifier[];
   source: Expression | null;
+  exportKind: 'type' | 'value';
 }
 
 export interface ExportSpecifier extends BaseNode {
@@ -949,6 +951,7 @@ export interface ImportDeclaration extends BaseNode {
   type: AST_NODE_TYPES.ImportDeclaration;
   source: Literal;
   specifiers: ImportClause[];
+  importKind: 'type' | 'value';
 }
 
 export interface ImportDefaultSpecifier extends BaseNode {

packages/typescript-estree/tests/ast-alignment/fixtures-to-test.ts

@@ -379,8 +379,8 @@ tester.addFixturePatternConfig('typescript/basics', {
      * But not fixed in Babel 7.3
      * TODO: Investigate differences
      */
-    'import-type',
-    'import-type-with-type-parameters-in-type-reference',
+    'type-import-type',
+    'type-import-type-with-type-parameters-in-type-reference',
     /**
      * Not yet supported in Babel https://github.com/babel/babel/issues/9228
      * Directive field is not added to module and namespace
@@ -422,6 +422,20 @@ tester.addFixturePatternConfig('typescript/basics', {
      */
     'abstract-class-with-declare-properties',
     'class-with-declare-properties',
+    /**
+     * TS 3.8 import/export type
+     * babel coming soon https://github.com/babel/babel/pull/11171
+     */
+    'export-type-as',
+    'export-type-from-as',
+    'export-type-from',
+    'export-type-star-from',
+    'export-type',
+    'import-type-default',
+    'import-type-error',
+    'import-type-named-as',
+    'import-type-named',
+    'import-type-star-as-ns',
   ],
   ignoreSourceType: [
     /**

packages/typescript-estree/tests/ast-alignment/utils.ts

@@ -248,6 +248,48 @@ export function preprocessBabylonAST(ast: BabelTypes.File): any {
           node.asserts = false;
         }
       },
+      /**
+       * TS 3.8 import/export type
+       * babel coming soon https://github.com/babel/babel/pull/11171
+       */
+      ExportNamedDeclaration(node: any) {
+        /**
+         * TS 3.8: export type
+         */
+        if (!node.exportKind) {
+          if (
+            node.declaration?.type === AST_NODE_TYPES.TSTypeAliasDeclaration ||
+            node.declaration?.type === AST_NODE_TYPES.TSInterfaceDeclaration
+          ) {
+            node.exportKind = 'type';
+          } else {
+            node.exportKind = 'value';
+          }
+        }
+      },
+      ExportAllDeclaration(node: any) {
+        /**
+         * TS 3.8: export type
+         */
+        if (!node.exportKind) {
+          if (
+            node.declaration?.type === AST_NODE_TYPES.TSTypeAliasDeclaration ||
+            node.declaration?.type === AST_NODE_TYPES.TSInterfaceDeclaration
+          ) {
+            node.exportKind = 'type';
+          } else {
+            node.exportKind = 'value';
+          }
+        }
+      },
+      ImportDeclaration(node) {
+        /**
+         * TS 3.8: export type
+         */
+        if (!node.importKind) {
+          node.importKind = 'value';
+        }
+      },
     },
   );
 }