fail the build if --tsconfig is missing (#330)

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+* Add an error message for a missing `--tsconfig` file ([#330](https://github.com/evanw/esbuild/issues/330))
+
+    The `--tsconfig` flag that was added in version 0.6.1 didn't report an error if the provided file doesn't actually exist. This release makes doing this an error that will fail the build.
+
 ## 0.6.22
 
 * The bell character is now escaped

internal/bundler/bundler_tsconfig_test.go

@@ -521,6 +521,21 @@ func TestTsconfigJsonOverrideNodeModules(t *testing.T) {
 	})
 }
 
+func TestTsconfigJsonOverrideInvalid(t *testing.T) {
+	tsconfig_suite.expectBundled(t, bundled{
+		files: map[string]string{
+			"/entry.ts": ``,
+		},
+		entryPaths: []string{"/entry.ts"},
+		options: config.Options{
+			IsBundling:       true,
+			AbsOutputFile:    "/out.js",
+			TsConfigOverride: "/this/file/doesn't/exist/tsconfig.json",
+		},
+		expectedScanLog: "error: Cannot find tsconfig file \"/this/file/doesn't/exist/tsconfig.json\"\n",
+	})
+}
+
 func TestTsconfigJsonNodeModulesImplicitFile(t *testing.T) {
 	tsconfig_suite.expectBundled(t, bundled{
 		files: map[string]string{

internal/resolver/resolver.go

@@ -634,7 +634,11 @@ func (r *resolver) dirInfoUncached(path string) *dirInfo {
 		}
 	} else if parentInfo == nil {
 		// If there is a tsconfig.json override, mount it at the root directory
-		info.tsConfigJson, _ = r.parseJsTsConfig(forceTsConfig, make(map[string]bool))
+		var status parseStatus
+		info.tsConfigJson, status = r.parseJsTsConfig(forceTsConfig, make(map[string]bool))
+		if status == parseReadFailure {
+			r.log.AddError(nil, ast.Loc{}, fmt.Sprintf("Cannot find tsconfig file %q", r.PrettyPath(forceTsConfig)))
+		}
 	}
 
 	// Propagate the enclosing tsconfig.json from the parent directory