fix #279: resolve implicit tsconfig.json base file

CHANGELOG.md

@@ -12,6 +12,10 @@
 
     Syntax trees with millions of sequential binary operators nested inside each other can cause the parser to stack overflow because it uses a recursive visitor pattern, so each binary operator added an entry to the call stack. Now code like this no longer triggers a stack overflow because the visitor uses the heap instead of the stack in this case. This is unlikely to matter in real-world code but can show up in certain artificial test cases, especially when `--minify-syntax` is enabled.
 
+* Resolve implicitly-named `tsconfig.json` base files ([#279](https://github.com/evanw/esbuild/issues/279))
+
+    The official TypeScript compiler lets you specify a package path as the `extends` property of a `tsconfig.json` file. The base file is then searched for in the relevant `node_modules` directory. Previously the package path had to end with the name of the base file. Now you can additionally omit the name of the base file if the file name is `tsconfig.json`. This more closely matches the behavior of the official TypeScript compiler.
+
 ## 0.6.8
 
 * Attempt to support the taobao.org registry ([#291](https://github.com/evanw/esbuild/issues/291))

internal/bundler/bundler_tsconfig_test.go

@@ -682,3 +682,36 @@ console.log("good");
 		},
 	})
 }
+
+func TestTsconfigJsonNodeModulesImplicitFile(t *testing.T) {
+	expectBundled(t, bundled{
+		files: map[string]string{
+			"/Users/user/project/src/app/entry.tsx": `
+				console.log(<div/>)
+			`,
+			"/Users/user/project/src/tsconfig.json": `
+				{
+					"extends": "foo"
+				}
+			`,
+			"/Users/user/project/src/node_modules/foo/tsconfig.json": `
+				{
+					"compilerOptions": {
+						"jsx": "react",
+						"jsxFactory": "worked"
+					}
+				}
+			`,
+		},
+		entryPaths: []string{"/Users/user/project/src/app/entry.tsx"},
+		options: config.Options{
+			IsBundling:    true,
+			AbsOutputFile: "/Users/user/project/out.js",
+		},
+		expected: map[string]string{
+			"/Users/user/project/out.js": `// /Users/user/project/src/app/entry.tsx
+console.log(/* @__PURE__ */ worked("div", null));
+`,
+		},
+	})
+}

internal/resolver/resolver.go

@@ -424,8 +424,9 @@ func (r *resolver) parseJsTsConfig(file string, visited map[string]bool) (*tsCon
 				for !found {
 					// Skip "node_modules" folders
 					if r.fs.Base(current) != "node_modules" {
-						extendsFile := r.fs.Join(current, "node_modules", extends)
-						for _, fileToCheck := range []string{extendsFile, extendsFile + ".json"} {
+						join := r.fs.Join(current, "node_modules", extends)
+						filesToCheck := []string{join, join + ".json", r.fs.Join(join, "tsconfig.json")}
+						for _, fileToCheck := range filesToCheck {
 							base, baseStatus := r.parseJsTsConfig(fileToCheck, visited)
 							if baseStatus == parseReadFailure {
 								continue