TypeScript + moment.js: error TS2307: Cannot find module 'moment'

Question

I'm developing a web app, using angular 1.5, typescript 2.4.0, moment: 2.18.1, and gulp for project assembling.

Here is my tsconfig.json:

{
  "files": [
    "src/app/main.ts",
    "types/**/*.ts"
  ],
  "compilerOptions": {
    "noImplicitAny": false,
    "target": "es2015",
    "allowSyntheticDefaultImports": true
  }
}

Inside my date-range-picker.component.ts. I'm importing moment lib, as was proposed in the main documentation:

import * as moment from 'moment'; 

Which works fine for the main gulp project assembling task that relies on tsify plugin.:

var browserifyIt = browserify({
    basedir: '.',
    debug: true,
    entries: paths.browserifyEntries,
    cache: {},
    packageCache: {}
}).plugin(tsify);

gulp.task('bundle', ['views'], function () {
    return browserifyIt
        .transform('babelify', {
            presets: ['es2015'],
            extensions: ['.ts']
        })
        .bundle()
        .on('error', interceptErrors)
        .pipe(source(fileNames.buildJs))
        .pipe(ngAnnotate())
        .pipe(buffer())
        .pipe(sourcemaps.init({loadMaps: true}))
        .pipe(sourcemaps.write(paths.sourcemapPath))
        .pipe(gulp.dest(paths.build));
});

But for the compiling of the tests I decided to use task employing tsProject():

const testSrcPaths = {
    ....,
    componentTests: 'src/app/components/**/*.test.ts',
    ....
};
gulp.task('component-tests:compile', function () {
       return gulp.src(testSrcPaths.componentTests).pipe(tsProject())
        .on('error', interceptErrors)
        .js.pipe(gulp.dest(`${paths.testsDist}/components`));
});

Which leads to the following error:

date-range-picker/date-range-picker.component.ts(2,25): error TS2307: Cannot find module 'moment'.

What can be done to fix it?

Answer 1

Finally, adding moduleResolution: "node" to compilerOptions solved my problem. So in the end the following tsconfig.json configuration is employed:

{
  "files": [
    "src/app/main.ts"
  ],
  "compilerOptions": {
    "noImplicitAny": false,
    "target": "es2015",
    "moduleResolution": "node"
  }
}

Here is the link one can use to learn more about typescript module resolution approaches.