javascript: resolve $lib, ~ and @ when the config only extends a framework's generated one

graph/test/javascript/cases/71-framework-generated-config-alias/src/kit/jsconfig.json

@@ -0,0 +1,4 @@
+{
+  "extends": "./.svelte-kit/tsconfig.json",
+  "compilerOptions": { "checkJs": true }
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/kit/src/lib/api.js

@@ -0,0 +1,7 @@
+export function get(path) {
+  return path;
+}
+
+export function post(path, body) {
+  return [path, body];
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/kit/src/routes/page.js

@@ -0,0 +1,11 @@
+// SvelteKit's $lib, mapped by the generated .svelte-kit/tsconfig.json that a checkout lacks
+import * as api from '$lib/api.js';
+import { post } from '$lib/api';
+
+export function load({ params }) {
+  return api.get(params.slug);
+}
+
+export function save(body) {
+  return post('/save', body);
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/nuxt/server/api/price.js

@@ -0,0 +1,7 @@
+// Nuxt's ~ and @, mapped by the generated .nuxt/tsconfig.json that a checkout lacks
+import { formatPrice } from '~/utils/price';
+import { formatPrice as viaAt } from '@/utils/price';
+
+export default function handler() {
+  return formatPrice(1) + viaAt(2);
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/nuxt/tsconfig.json

@@ -0,0 +1 @@
+{ "extends": "./.nuxt/tsconfig.json" }

graph/test/javascript/cases/71-framework-generated-config-alias/src/nuxt/utils/price.js

@@ -0,0 +1,3 @@
+export function formatPrice(n) {
+  return n;
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/nuxt4/app/pages/index.js

@@ -0,0 +1,6 @@
+// Nuxt 4: the source dir is app/, and the root config only references the generated ones
+import { formatDate } from '~/utils/date';
+
+export function page(d) {
+  return formatDate(d);
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/nuxt4/app/utils/date.js

@@ -0,0 +1,3 @@
+export function formatDate(d) {
+  return d;
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/nuxt4/tsconfig.json

@@ -0,0 +1,4 @@
+{
+  "files": [],
+  "references": [{ "path": "./.nuxt/tsconfig.app.json" }, { "path": "./.nuxt/tsconfig.server.json" }]
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/other/jsconfig.json

@@ -0,0 +1 @@
+{ "extends": "./.config/tsconfig.json" }

graph/test/javascript/cases/71-framework-generated-config-alias/src/other/probe.js

@@ -0,0 +1,6 @@
+// CONTROL: a missing extended config that no framework generates maps nothing
+import { helper } from '$lib/helper';
+
+export function probe() {
+  return helper();
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/other/src/lib/helper.js

@@ -0,0 +1,3 @@
+export function helper() {
+  return 1;
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/own/jsconfig.json

@@ -0,0 +1,4 @@
+{
+  "extends": "./.svelte-kit/tsconfig.json",
+  "compilerOptions": { "baseUrl": ".", "paths": { "$lib/*": ["./shared/*"] } }
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/own/probe.js

@@ -0,0 +1,6 @@
+// CONTROL: the project maps $lib itself, and its own paths win over any framework default
+import { pick } from '$lib/util';
+
+export function chosen() {
+  return pick();
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/own/shared/util.js

@@ -0,0 +1,3 @@
+export function pick() {
+  return 2;
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/own/src/lib/util.js

@@ -0,0 +1,3 @@
+export function pick() {
+  return 1;
+}

graph/test/javascript/cases/71-framework-generated-config-alias/src/package.json

@@ -0,0 +1 @@
+{ "name": "framework-alias-fixture", "type": "module" }

graph/test/javascript/expected/71-framework-generated-config-alias.diag

@@ -0,0 +1,3 @@
+import_cause     other/probe.js:2:10  $lib/helper  not_staged
+package_entry    framework-alias-fixture  .  []  DEFAULT_INDEX  index.js  MISSING_FILE  -> -
+unresolved       other/probe.js:5:10  FUNCTION_CALL helper  callee_untyped

graph/test/javascript/expected/71-framework-generated-config-alias.edges

@@ -0,0 +1,7 @@
+kit/src/routes/page.js:10:10 FUNCTION_CALL post  ->  known_edge  kit/src/lib/api.js:5:1 post
+kit/src/routes/page.js:6:10 METHOD_CALL api.get  ->  known_edge  kit/src/lib/api.js:1:1 get
+nuxt/server/api/price.js:6:10 FUNCTION_CALL formatPrice  ->  known_edge  nuxt/utils/price.js:1:1 formatPrice
+nuxt/server/api/price.js:6:27 FUNCTION_CALL viaAt  ->  known_edge  nuxt/utils/price.js:1:1 formatPrice
+nuxt4/app/pages/index.js:5:10 FUNCTION_CALL formatDate  ->  known_edge  nuxt4/app/utils/date.js:1:1 formatDate
+other/probe.js:5:10 FUNCTION_CALL helper  ->  ambiguous_unknown  -
+own/probe.js:5:10 FUNCTION_CALL pick  ->  known_edge  own/shared/util.js:1:1 pick

graph/test/javascript/expected/71-framework-generated-config-alias.oracle

@@ -0,0 +1 @@
+# defects: 0

parser/src/test/javascript-tests.ts

@@ -3210,6 +3210,13 @@ async function pathAliasesResolveThroughTheNearestConfig(): Promise<number> {
   write('remix/app/route.js', "import { getNote } from '~/models/note.server';\n");
   write('plain/jsconfig.json', '{ "compilerOptions": { "checkJs": true } }');
   write('plain/probe.js', "import { checkA } from '@/lib/check';\n");
+  // a config that only extends the framework's generated one, absent from a checkout (#1756)
+  write('kit/jsconfig.json', '{ "extends": "./.svelte-kit/tsconfig.json" }');
+  write('kit/src/lib/api.js', 'export function get() { return 1; }\n');
+  write('kit/src/routes/page.js', "import * as api from '$lib/api.js';\n");
+  write('other/jsconfig.json', '{ "extends": "./.config/tsconfig.json" }');
+  write('other/src/lib/api.js', 'export function get() { return 1; }\n');
+  write('other/probe.js', "import * as api from '$lib/api.js';\n");
   await new JavaScriptProjectAnalyzer().analyzeAll([root], { outputDir: out, baseMservPath: root, serviceVersionLink: 'gate-v1' });
   const relations = readRelations(out);
   const imports = relations.find((r) => r.name === 'js_import');
@@ -3225,6 +3232,8 @@ async function pathAliasesResolveThroughTheNearestConfig(): Promise<number> {
     ['src/app.js', './lib/check.js', 'RESOLVED_PROJECT', 'src/lib/check'],
     ['remix/app/route.js', '~/models/note.server', 'RESOLVED_PROJECT', 'remix/app/models/note.server'],
     ['plain/probe.js', '@/lib/check', 'UNRESOLVED_MISSING', ''],
+    ['kit/src/routes/page.js', '$lib/api.js', 'RESOLVED_PROJECT', 'kit/src/lib/api'],
+    ['other/probe.js', '$lib/api.js', 'UNRESOLVED_MISSING', ''],
   ];
   for (const [file, specifier, wantOutcome, target] of want) {
     const rows = imports.rows.filter((row) => fileOf.get(row[owner] ?? '') === file && row[spec] === specifier);

parser/src/workflows/javascript/javascript-project-analyzer.ts

@@ -683,10 +683,61 @@ function readPathAliases(configPath: string): PathAliases {
   if (options.paths !== undefined) {
     aliases.paths = options.paths;
     aliases.pathsBasePath = options.pathsBasePath;
+  } else {
+    const generated = frameworkDefaultAliases(read.config, path.dirname(configPath));
+    if (generated !== undefined) {
+      aliases.paths = generated;
+      aliases.pathsBasePath = path.dirname(configPath);
+    }
   }
   return aliases;
 }
 
+/**
+ * The aliases a framework's GENERATED config would have supplied, when the project's
+ * config `extends` (or `references`) one that a checkout does not contain.
+ *
+ * SvelteKit writes `.svelte-kit/tsconfig.json` and Nuxt `.nuxt/tsconfig*.json` at
+ * dev/build time; the project's own config only points at them, so without this every
+ * `$lib/api` or `~/utils/price` import was UNRESOLVED_MISSING (#1756). The mapping is the
+ * framework's default one: SvelteKit `$lib` → `src/lib`; Nuxt `~`, `@` → the source dir
+ * (`app/` first, as Nuxt 4 lays it out, then the root) and `~~`, `@@` → the root. A
+ * generated config that IS present is read as written, and a project `paths` wins.
+ */
+function frameworkDefaultAliases(config: unknown, configDirectory: string): ts.MapLike<string[]> | undefined {
+  const { extends: extended, references } = (config ?? {}) as { extends?: unknown; references?: unknown };
+  const named = [
+    ...(Array.isArray(extended) ? extended : [extended]),
+    ...(Array.isArray(references) ? references.map((r) => (r as { path?: unknown } | null)?.path) : []),
+  ].filter((p): p is string => typeof p === 'string');
+  for (const pointed of named) {
+    const target = path.resolve(configDirectory, pointed);
+    // `./.nuxt/tsconfig.app.json`, `./.nuxt/tsconfig` (extension implied), or a
+    // `references` directory, which means its tsconfig.json
+    const namesFile = path.basename(target).startsWith('tsconfig');
+    const configFile = !namesFile ? path.join(target, 'tsconfig.json')
+      : target.endsWith('.json') ? target : `${target}.json`;
+    const generatedDirectory = path.dirname(configFile);
+    if (fs.existsSync(configFile) || path.dirname(generatedDirectory) !== configDirectory) {
+      continue;
+    }
+    const framework = path.basename(generatedDirectory);
+    if (framework === '.svelte-kit') {
+      return { '$lib': ['./src/lib'], '$lib/*': ['./src/lib/*'] };
+    }
+    if (framework === '.nuxt') {
+      const source = ['./app', '.'];
+      const root = ['.'];
+      const under = (dirs: string[]) => dirs.map((d) => `${d}/*`);
+      return {
+        '~': source, '~/*': under(source), '@': source, '@/*': under(source),
+        '~~': root, '~~/*': under(root), '@@': root, '@@/*': under(root),
+      };
+    }
+  }
+  return undefined;
+}
+
 /**
  * Every emitted path hangs off this, not off `rootDir`.
  *