Cannot read property 'length' of undefined on 3.1.6

[amiramw]

When running gulp default I get an exception when using gulp-typescript 3.1.6:

TypeError: Cannot read property 'length' of undefined
    at Object.writeFile (C:\Users\i066470\repos\storyboard\node_modules\gulp-typescript\release\compiler.js:64:32)
    at Object.writeFile (C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:8619:14)
    at printFile (C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:56633:20)
    at emitFile (C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:56590:21)
    at onSingleFileEmit (C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:8526:13)
    at Object.forEachTransformedEmitFile (C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:8503:21)
    at Object.emitFiles (C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:56573:12)
    at emitWorker (C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:59447:33)
    at C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:59410:66
    at runWithCancellationToken (C:\Users\i066470\repos\storyboard\node_modules\typescript\lib\typescript.js:59492:24)

Everything works fine when changing gulp-typescript to version 3.1.5.

Gulp file:

var gulp = require("gulp");
var ts = require("gulp-typescript");
var sourcemaps = require('gulp-sourcemaps');

var tsProject = ts.createProject("tsconfig.json");
var SRC_GLOB = 'src/**/*';
var TEST_GLOB = 'tests/**/*';
var DEFS_GLOB = 'defs/**/*';

gulp.task("compile", function () {
	return tsProject.src().pipe(sourcemaps.init())
		.pipe(tsProject()).once("error", function () {
			this.once("finish", function () {
				process.exit(1);
			});
		})
		.js
		.pipe(sourcemaps.write())
		.pipe(gulp.dest("compiled"));
});

gulp.task("compile-no-fail", function () {
	return tsProject.src().pipe(sourcemaps.init())
		.pipe(tsProject())
		.js
		.pipe(sourcemaps.write())
		.pipe(gulp.dest("compiled"));
});

gulp.task("copy", function () {
	gulp.src(SRC_GLOB).pipe(gulp.dest("compiled/src"));
	gulp.src(TEST_GLOB).pipe(gulp.dest("compiled/tests"));
});

gulp.task('watch', function() {
	gulp.watch([SRC_GLOB, TEST_GLOB, DEFS_GLOB], ['watch-compilation']);
});

gulp.task('watch-compilation', ['compile-no-fail', 'copy']);

gulp.task('default', ['compile', 'copy']);

tsconfig.json:

{
	"compilerOptions": {
		"baseUrl": "",
		"paths": {
			"sap/watt/platform/plugin/platform/service/ui/AbstractPart": [
				"defs/watt/AbstractPart"
			],
			"sap.watt.common.perspective/command/PerspectiveSwitcher": [
				"defs/watt/PerspectiveSwitcher"
			],
			"sap/watt/core/I18nBundle": [
				"defs/watt/I18nBundle"
			],
			"sap.watt.saptoolsets.fiori.common.storyboard/*": [
				"src/storyboard_core/*"
			],
			"STF": [
				"defs/watt/STF"
			],
			"sinon": [
				"defs/watt/sinon"
			]
		},
		"noEmitOnError": true,
		"module": "amd",
		"target": "es5",
		"sourceMap": true,
		"declaration": false,
		"traceResolution": true,
		"outDir": "compiled",
		"alwaysStrict": true,
		"forceConsistentCasingInFileNames": true,
		"noImplicitReturns": true,
		"noImplicitThis": true,
		"allowJs": true
	},
	"include": [
		"src/**/*",
		"defs/**/*",
		"tests/**/*"
	],
	"exclude": [
		"node_modules"
	]
}

[ivogabe]

Which version of TypeScript are you using?

[amiramw]

2.1.1

[ivogabe]

@vladima Any idea why the sourceFiles argument of WriteFileCallback can be undefined? I see that it's marked optional in its definition:

export interface WriteFileCallback {
    (fileName: string, data: string, writeByteOrderMark: boolean, onError?: (message: string) => void, sourceFiles?: SourceFile[]): void;
}

Is there some way to force it being set?

[SET001]

same problem here
tsc Version 2.3.0-dev.20170401
gulp-typescript 3.1.6

[SET001]

Solved after I reinstalled typesript package

[ivogabe]

Is this still an issue to someone?

[amiramw]

Seems solved with typescript 2.1.5

[judemanutd]

@ivogabe Got the same error

Current config

typescript : 3.6.2
gulp : 4.0.2
gulp-typescript : 5.0.1

var gulp = require("gulp");
var del = require("del");
var ts = require("gulp-typescript");
var tsProject = ts.createProject("tsconfig.json", {
  typescript: require("typescript"),
});

gulp.task("clean_tmp", function() {
  return del("tmp/**", { force: true });
});

gulp.task("build", function() {
  return tsProject
    .src()
    .pipe(tsProject())
    .js.pipe(gulp.dest("tmp"));
});

gulp.task("clean_dist", function() {
  return del("dist/**", { force: true });
});

gulp.task("move_dist", function() {
  return gulp.src("tmp/**").pipe(gulp.dest("dist"));
});

gulp.task("assets_copy", function() {
  return gulp
    .src([
      "src/ofm-auto.testing.json",
      "src/serviceAccountKey.json",
      "src/firebase-service-account.json",
    ])
    .pipe(gulp.dest("dist"));
});

gulp.task("views_copy", function() {
  return gulp.src(["src/views/**/*"]).pipe(gulp.dest("dist/views"));
});

gulp.task(
  "default",
  gulp.series(
    "clean_tmp",
    "build",
    "clean_dist",
    "move_dist",
    "assets_copy",
    "views_copy",
    "clean_tmp",
  ),
);

tsconfig.json

{
  "compilerOptions": {
    "incremental": true,
    "module": "commonjs",
    "esModuleInterop": true,
    "target": "es2018",
    "noImplicitAny": false,
    "removeComments": true,
    "resolveJsonModule": true,
    "moduleResolution": "node",
    "sourceMap": true,
    "outDir": "dist/",
    "pretty": true,
    "baseUrl": ".",
    "alwaysStrict": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "traceResolution": false,
    "paths": {
      "*": ["node_modules/*", "*"]
    },
    "types": ["jest", "node"]
  },
  "include": ["src/**/*.ts"],
  "exclude": [".git", "node_modules"]
}

[rostacik]

it seems the incremental prop is the culprit here.

this worked for me :
http://quabr.com/58031957/typescript-throws-a-cannot-read-property-length-of-undefined-when-run-throug