Support import paths with .gts extensions

Fixes #618

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
       - name: Install Node
         uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 16
       - name: Locate Yarn Cache
         id: yarn-cache-dir-path
         run: echo "dir=$(yarn cache dir)" >> $GITHUB_OUTPUT
@@ -60,7 +60,7 @@ jobs:
       - name: Install Node
         uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 16
       - name: Install Dependencies
         uses: nick-fields/retry@v2
         with:
@@ -93,7 +93,7 @@ jobs:
       - name: Install Node
         uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 16
       - name: Install Dependencies
         run: yarn install --no-lockfile
       - name: Build
@@ -112,7 +112,7 @@ jobs:
       - name: Install Node
         uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 16
       - name: Locate Yarn Cache
         id: yarn-cache-dir-path
         run: echo "dir=$(yarn cache dir)" >> $GITHUB_OUTPUT

packages/core/src/common/document-cache.ts

@@ -58,8 +58,15 @@ export default class DocumentCache {
     );
   }
 
+  private gtsAwareExtName(filename: string): string {
+    if (filename.endsWith('.gts.ts')) {
+      return '.gts.ts';
+    }
+    return path.extname(filename);
+  }
+
   public getCandidateDocumentPaths(filename: string): Array<string> {
-    let extension = path.extname(filename);
+    let extension = this.gtsAwareExtName(filename);
     let filenameWithoutExtension = filename.slice(0, filename.lastIndexOf(extension));
 
     return this.getCandidateExtensions(filename).map((ext) => `${filenameWithoutExtension}${ext}`);

packages/core/src/config/types.cts

@@ -24,6 +24,7 @@ export type GlintExtensionPreprocess<T> = (
 export type GlintEmitMetadata = {
   prepend?: string;
   append?: string;
+  replaceExtension?: string;
   templateLocation?: {
     start: number;
     end: number;
@@ -37,7 +38,10 @@ export type GlintExtensionTransform<T> = (
   state: {
     ts: TSLib;
     context: ts.TransformationContext;
-    setEmitMetadata: (node: ts.TaggedTemplateExpression, meta: GlintEmitMetadata) => void;
+    setEmitMetadata: (
+      node: ts.TaggedTemplateExpression | ts.ImportDeclaration,
+      meta: GlintEmitMetadata
+    ) => void;
   }
 ) => ts.Transformer<ts.Node>;
 

packages/core/src/transform/template/import-declaration-span.ts

@@ -0,0 +1,54 @@
+import * as ts from 'typescript';
+import { TSLib } from '../util.js';
+import { CorrelatedSpansResult, PartialCorrelatedSpan } from './inlining/index.js';
+import { Directive, SourceFile, TransformError } from './transformed-module.js';
+import { GlintEmitMetadata } from '@glint/core/config-types';
+import MappingTree, { GtsImport } from './mapping-tree.js';
+
+const tsPrinter = ts.createPrinter();
+
+export function calculateImportSpan(
+  ts: TSLib,
+  node: ts.ImportDeclaration,
+  meta: GlintEmitMetadata | undefined,
+  script: SourceFile
+): CorrelatedSpansResult {
+  let directives: Array<Directive> = [];
+  let errors: Array<TransformError> = [];
+  let partialSpans: Array<PartialCorrelatedSpan> = [];
+  let moduleSpecifierText = (node.moduleSpecifier as ts.StringLiteral).text;
+  if (meta?.replaceExtension) {
+    let newModuleSpecifier = ts.factory.createStringLiteral(
+      moduleSpecifierText.replace(/\.gts$/, '.' + meta.replaceExtension)
+    );
+    let updatedNode = ts.factory.updateImportDeclaration(
+      node,
+      node.modifiers,
+      node.importClause,
+      newModuleSpecifier,
+      node.assertClause
+    );
+    let originalStart = node.getStart();
+    let originalLength = node.getEnd() - originalStart;
+    let transformedSource = tsPrinter.printNode(
+      ts.EmitHint.Unspecified,
+      updatedNode,
+      node.getSourceFile()
+    );
+    partialSpans.push({
+      originalFile: script,
+      originalStart,
+      originalLength,
+      insertionPoint: originalStart,
+      transformedSource,
+      mapping: new MappingTree(
+        { start: 0, end: transformedSource.length },
+        { start: 0, end: originalLength },
+        [],
+        new GtsImport()
+      ),
+    });
+  }
+
+  return { errors, directives, partialSpans };
+}

packages/core/src/transform/template/mapping-tree.ts

@@ -2,7 +2,13 @@ import { AST } from '@glimmer/syntax';
 import { Range } from './transformed-module.js';
 import { Identifier } from './map-template-contents.js';
 
-export type MappingSource = AST.Node | TemplateEmbedding | TextContent | Identifier | ParseError;
+export type MappingSource =
+  | AST.Node
+  | TemplateEmbedding
+  | TextContent
+  | Identifier
+  | GtsImport
+  | ParseError;
 
 /**
  * In cases where we're unable to parse a template, we still want to
@@ -34,6 +40,13 @@ export class TemplateEmbedding {
   public readonly type = 'TemplateEmbedding';
 }
 
+/**
+ * This node represents an import declaration of a .gts file.
+ */
+export class GtsImport {
+  public readonly type = 'GtsImport';
+}
+
 /**
  * A `MappingTree` maintains a hierarchy of mappings between ranges of
  * locations in original and transformed source strings. These mappings
@@ -109,23 +122,23 @@ export default class MappingTree {
   }): string {
     let { originalSource, transformedSource, indent = '| ' } = options;
     let { sourceNode, originalRange, transformedRange, children } = this;
-    let hbsStart = options.originalStart + originalRange.start;
-    let hbsEnd = options.originalStart + originalRange.end;
+    let sourceStart = options.originalStart + originalRange.start;
+    let sourceEnd = options.originalStart + originalRange.end;
     let tsStart = options.transformedStart + transformedRange.start;
     let tsEnd = options.transformedStart + transformedRange.end;
     let lines = [];
 
     lines.push(`${indent}Mapping: ${sourceNode.type}`);
 
+    let sourceDesc = sourceNode.type === 'GtsImport' ? 'ts' : 'hbs';
     lines.push(
-      `${indent}${` hbs(${hbsStart}:${hbsEnd}):`.padEnd(15)}${this.getSourceRange(
-        originalSource,
-        originalRange
-      )}`
+      `${indent}${` in: ${sourceDesc}(${sourceStart}:${sourceEnd}):`.padEnd(
+        20
+      )}${this.getSourceRange(originalSource, originalRange)}`
     );
 
     lines.push(
-      `${indent}${` ts(${tsStart}:${tsEnd}):`.padEnd(15)}${this.getSourceRange(
+      `${indent}${` out: ts(${tsStart}:${tsEnd}):`.padEnd(20)}${this.getSourceRange(
         transformedSource,
         transformedRange
       )}`

packages/core/src/transform/template/rewrite-module.ts

@@ -12,6 +12,7 @@ import TransformedModule, {
 } from './transformed-module.js';
 import { calculateTaggedTemplateSpans } from './inlining/tagged-strings.js';
 import { calculateCompanionTemplateSpans } from './inlining/companion-file.js';
+import { calculateImportSpan } from './import-declaration-span.js';
 
 /**
  * Input to the process of rewriting a template, containing one or both of:
@@ -86,8 +87,13 @@ function calculateCorrelatedSpans(
         } else if (ts.isModuleDeclaration(node)) {
           // don't traverse into declare module
           return node;
+        } else if (ts.isImportDeclaration(node) && ts.isStringLiteral(node.moduleSpecifier)) {
+          let meta = emitMetadata.get(node);
+          let result = calculateImportSpan(ts, node, meta, script);
+          directives.push(...result.directives);
+          errors.push(...result.errors);
+          partialSpans.push(...result.partialSpans);
         }
-
         return ts.visitEachChild(node, visit, context);
       },
   ]);

packages/environment-ember-template-imports/-private/environment/transform.ts

@@ -22,6 +22,13 @@ export const transform: GlintExtensionTransform<PreprocessData> = (
     if (ts.isSourceFile(node)) {
       // Add `import { hbs as __T } from 'ember-template-imports'` to the file
       return addTagImport(f, node);
+    } else if (ts.isImportDeclaration(node) && ts.isStringLiteral(node.moduleSpecifier)) {
+      if (node.moduleSpecifier.text.endsWith('.gts')) {
+        setEmitMetadata(node, {
+          replaceExtension: 'ts',
+        });
+      }
+      return node;
     } else if (isETIDefaultTemplate(ts, node)) {
       // Annotate that this template is a default export
       setEmitMetadata(node.expression, { prepend: 'export default ' });

test-packages/ts-template-imports-app/src/Greeting.gts → test-packages/ts-template-imports-app/app/components/Greeting.gts

@@ -1,5 +1,6 @@
 import Component from '@glimmer/component';
 import { TOC } from '@ember/component/template-only';
+import repeat from '../helpers/repeat';
 
 export interface GreetingSignature {
   Args: { target: string };
@@ -13,10 +14,12 @@ export default class Greeting extends Component<GreetingSignature> {
   </template>
 }
 
-function repeat(value: string, times: number): string {
-  return Array(times).fill(value).join('');
-}
-
 const Bang: TOC<{ Args: { times: number } }> = <template>
   {{repeat '!' @times}}
 </template>
+
+declare module '@glint/environment-ember-loose/registry' {
+  export default interface Registry {
+    Greeting: typeof Greeting;
+  }
+}

test-packages/ts-template-imports-app/src/index.gts → test-packages/ts-template-imports-app/app/components/WorldGreeting.gts

@@ -1,4 +1,4 @@
-import Greeting from './Greeting';
+import Greeting from './Greeting.gts';
 
 export default <template>
   <Greeting @target="World" />

test-packages/ts-template-imports-app/app/helpers/repeat.ts

@@ -0,0 +1,4 @@
+export default function repeat(value: string, times: number): string {
+  return value.repeat(times);
+}
+

test-packages/ts-template-imports-app/app/templates/application.hbs

@@ -0,0 +1,3 @@
+<div class="main">
+  <Greeting @target="Earthling" />
+</div>

test-packages/ts-template-imports-app/package.json

@@ -4,7 +4,17 @@
   "private": true,
   "license": "MIT",
   "scripts": {
-    "test": "glint"
+    "test": "npm-run-all test:*",
+    "test:typecheck": "glint",
+    "test:tsc": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "@typescript-eslint/eslint-plugin": "~6.7.2",
+    "@typescript-eslint/parser": "~6.7.2",
+    "typescript": "~5.2.0"
+  },
+  "engines": {
+    "node": ">= 16"
   },
   "volta": {
     "extends": "../../package.json"

test-packages/ts-template-imports-app/tsconfig.json

@@ -1,6 +1,10 @@
 {
   "extends": "../../tsconfig.compileroptions.json",
-  "include": ["src", "types"],
+  "compilerOptions": {
+    "allowImportingTsExtensions": true,
+    "noEmit": true
+  },
+  "include": ["app", "types"],
   "glint": {
     "environment": {
       "ember-loose": {},