gulp-expect-file

gulp-expect-file

Expectation on generated files for gulp 3/4

This plugin is intended for testing other gulp plugin.

Usage

First, install gulp-expect-file as a development dependency:

npm install --save-dev gulp-expect-file

Then, add it to your gulpfile.js:

var expect = require("gulp-expect-file");

gulp.task("copy", function () {
  gulp
    .src(["src/foo.txt"])
    .pipe(gulp.dest("dest/"))
    .pipe(expect("dest/foo.txt"));
});

API

expect(expectation)

expectation

Type: String, Array, Object or Function

It describes the expectation of files on pipe.

expectation	meaning
"foo.txt"	Expects foo.txt on pipe
"*.txt"	Expects any files matching glob *.txt on pipe
["a.txt", "b.txt"]	Expects a.txt and b.txt both on pipe
{"a.txt": true, "b.txt": true}	Expects a.txt and b.txt both on pipe (same as above)
{"foo.txt": "text"}	Expects foo.txt with contents that has "text" as substring
{"foo.txt": /pattern/}	Expects foo.txt with contents that matches /pattern/
function (file) { ... }	Call the tester function for each file on pipe
{"foo.txt": function (file) { ... }}	Call the tester function for foo.txt

A tester function is called with vinyl File object of target file.

It can return true, null, undefined for passing that file. false, String of error message, or any other value will fail testing on that file.

Sync version:

function (file) {
  return /\.txt$/.test(file.path);
}

Async version:

function (file, callback) {
  process.nextTick(function () {
    if (/\.txt$/.test(file.path)) {
      callback('not txt file');
    } else {
      callback();
    }
  });
}

expect(options, expectation)

options.reportUnexpected

Type: Boolean Default: true

If true, files not matching any expectation will be reported as failure.

For example, if a.txt and b.txt are on the pipe, expect(['a.txt']) will report that b.txt is unexpected.

gulp.src(["a.txt", "b.txt"]).pipe(expect(["a.txt"]));

// => FAIL: b.txt unexpected

options.reportMissing

Type: Boolean Default: true

If true, expected files that are not on the pipe will be reported as failure.

For example, if a.txt is on the pipe, expect(['a.txt', 'b.txt']) will report that b.txt is missing.

gulp.src(["a.txt"]).pipe(expect(["a.txt", "b.txt"]));

// => FAIL: Missing 1 expected files: b.txt

options.checkRealFile

Type: Boolean Default: false

If true, it also checks if the real file exists on the file system by fs.exists().

gulp
  .src(["exist.txt", "nonexist.txt"])
  .pipe(expect({ checkRealFile: true }, "*.txt"));

// => FAIL: nonexist.txt not exists on filesystem

options.errorOnFailure

Type: Boolean Default: false

If true, it emits error event when expectations got failed.

gulp
  .src(["a.txt"])
  .pipe(expect({ errorOnFailure: true }, ["b.txt"]))
  .on("error", function (err) {
    console.error(err);
  });

options.silent

Type: Boolean Default: false

If true, it does not report any results.

options.verbose

Type: Boolean Default: false

If true, it reports files that passed the expectation.

expect.real([options,] expectation)

This is just a shortcut for expect({ checkRealFile: true }, expectation).