Getting error "TypeScript: emit failed" when using allowJs option in typescript@next

[mohitspawar]

I am using typescript@next (Version 1.8.0-dev.20160108) with tsconfig.json as

{
    "compileOnSave": false,
    "filesGlob": [
        "./src/**/*.ts",
        "./src/**/*.js",
        "!./node_modules/**/*.ts",
        "!./node_modules/**/*.js"
    ],
    "compilerOptions": {
        "allowJs": true,
        "target": "es5",
        "module": "amd",
        "outdir": "./output",
        "declaration": false,
        "noImplicitAny": false,
        "noResolve": true,
        "removeComments": true,
        "noLib": false,
        "emitDecoratorMetadata": true,
        "experimentalDecorators": true
    }
}

I am trying to use the allowJs option to transpile .js files.
The build task is failing with error "TypeScript: emit failed". There is no other information.
I am not sure how to get more information about the error.

Does gulp-typescript support the allowJS option ? Do I have to do anything different for js files ?

This is my build task:

gulp.task('ts:build', function () {
  var tsResult =  gulp.src(['src/**/*.ts', 'src/**/*.d.ts', 'src/**/*.js'])
    .pipe(print())
    .pipe( sourcemaps.init({ loadMaps: true }))
    .pipe(ts(tsProject));

  return merge([
    tsResult.dts
    .pipe(gulp.dest(paths.output.typings)),

    tsResult.js
    .pipe(sourcemaps.write({ includeContent: true }))
    .pipe(gulp.dest('output'))
  ]); 
});

[ivogabe]

How did you define tsProject? It should include a reference to your typescript installation, like this:

var tsProject = ts.createProject('tsconfig.json', { typescript: require('typescript') });

[mohitspawar]

Yes. That is how I have defined tsProject.

var tsProject = ts.createProject('./tsconfig.json', {
  typescript:  require('typescript'),
  noExternalResolve: true
});

[stephenlautier]

I'm also getting this issue and im not using allowJs and im using typescript 1.8.0. For some reason errors are not emitted

This is what I have

// tsconfig

{
    "compilerOptions": {
        "module": "amd",
        "target": "es5",
        "noImplicitAny": true,
        "noEmit": true,
        "noLib": false,
        "emitDecoratorMetadata": true,
        "experimentalDecorators": true,
        "declaration": false
    },
    "exclude": [
        "node_modules",
        "dist",
        "_artifact"
    ]
}

// gulp

function getTscOptions() {
    var typescript = require("typescript");
    return $.typescript.createProject("tsconfig.json", {
        sortOutput: true,
        typescript: typescript
    });
}

gulp.task("compile:ts", () => {

    const tsProject = getTscOptions();
    const tsResult = gulp.src([config.src.tsd, config.src.ts, `!${config.test.files}`])
        .pipe($.plumber())
        .pipe($.sourcemaps.init())
        .pipe($.typescript(tsProject));

    return $.merge2([
        tsResult.js
            .pipe($.ngAnnotate())
            .pipe($.sourcemaps.write("."))
            .pipe(gulp.dest(`${config.artifact}/amd`))
    ]);
});

[stephenlautier]

Sorry from my end seems to be working now, I simply changed "noEmit": false

[ivogabe]

Are you using the latest version of gulp-typescript?

[ivogabe]

@stephenlautier Ow wait, I think you're mistaking noEmit with noEmitOnError. The latter prevents emit when there is a build error, whereas noEmit just never emits a file.

[stephenlautier]

Should be, I'm using v2.10.0 of gulp-typescript. but as I said by simply changing the "noEmit": false (before it was true) its working fine.
Simply the behaviour changed from the previous version for anyone who have the same issue which I had (might be from TSC itself).

@ivogabe Correct, I'm not mistaking it however, i just had that one set previously and it used to work still on typescript 1.7.x, now it doesn't which I believe its the correct way