Minor improvements on the usage of fs utilities - unify all the fs functions into the same util/fs to simplify things (#3749)

bin/cli.js

@@ -7,8 +7,6 @@ const tildify = require('tildify');
 const commander = require('commander');
 const color = require('colorette');
 const argv = require('getopts')(process.argv.slice(2));
-const fs = require('fs');
-const { promisify } = require('util');
 const cliPkg = require('../package');
 const {
   mkConfigObj,
@@ -20,14 +18,10 @@ const {
   getSeedExtension,
   getStubPath,
 } = require('./utils/cli-config-utils');
+const { readFile, writeFile } = require('./../lib/util/fs');
 
 const { listMigrations } = require('./utils/migrationsLister');
 
-const fsPromised = {
-  readFile: promisify(fs.readFile),
-  writeFile: promisify(fs.writeFile),
-};
-
 function openKnexfile(configPath) {
   const config = require(configPath);
 
@@ -118,15 +112,14 @@ function invoke(env) {
       }
       checkLocalModule(env);
       const stubPath = `./knexfile.${type}`;
-      pending = fsPromised
-        .readFile(
-          path.dirname(env.modulePath) +
-            '/lib/migrate/stub/knexfile-' +
-            type +
-            '.stub'
-        )
+      pending = readFile(
+        path.dirname(env.modulePath) +
+          '/lib/migrate/stub/knexfile-' +
+          type +
+          '.stub'
+      )
         .then((code) => {
-          return fsPromised.writeFile(stubPath, code);
+          return writeFile(stubPath, code);
         })
         .then(() => {
           success(color.green(`Created ${stubPath}`));

lib/migrate/sources/fs-migrations.js

@@ -1,9 +1,7 @@
-const fs = require('fs');
 const path = require('path');
-const { promisify } = require('util');
 const { sortBy, filter } = require('lodash');
 
-const readDirAsync = promisify(fs.readdir);
+const { readdir } = require('../../util/fs');
 
 const DEFAULT_LOAD_EXTENSIONS = Object.freeze([
   '.co',
@@ -35,7 +33,7 @@ class FsMigrations {
     // Get a list of files in all specified migration directories
     const readMigrationsPromises = this.migrationsPaths.map((configDir) => {
       const absoluteDir = path.resolve(process.cwd(), configDir);
-      return readDirAsync(absoluteDir).then((files) => ({
+      return readdir(absoluteDir).then((files) => ({
         files,
         configDir,
         absoluteDir,

lib/seed/Seeder.js

@@ -1,11 +1,9 @@
 // Seeder
 // -------
 
-const fs = require('fs');
 const path = require('path');
-const { promisify } = require('util');
 const { filter, includes, extend } = require('lodash');
-const { ensureDirectoryExists } = require('../util/fs');
+const { readdir, ensureDirectoryExists } = require('../util/fs');
 const { writeJsFileUsingTemplate } = require('../util/template');
 
 // The new seeds we're performing, typically called from the `knex.seed`
@@ -42,7 +40,7 @@ class Seeder {
   async _listAll(config) {
     this.config = this.setConfig(config);
     const loadExtensions = this.config.loadExtensions;
-    return promisify(fs.readdir)(this._absoluteConfigDir()).then((seeds) =>
+    return readdir(this._absoluteConfigDir()).then((seeds) =>
       filter(seeds, (value) => {
         const extension = path.extname(value);
         return includes(loadExtensions, extension);

lib/util/fs.js

@@ -4,13 +4,11 @@ const path = require('path');
 const { promisify } = require('util');
 const mkdirp = require('mkdirp');
 
-/**
- * Promisified version of fs.stat() function.
- *
- * @param {string} path
- * @returns {Promise}
- */
+// Promisify common fs functions.
 const stat = promisify(fs.stat);
+const readFile = promisify(fs.readFile);
+const writeFile = promisify(fs.writeFile);
+const readdir = promisify(fs.readdir);
 
 /**
  * Creates a temporary directory and returns it path.
@@ -35,6 +33,9 @@ function ensureDirectoryExists(dir) {
 
 module.exports = {
   stat,
+  readdir,
+  readFile,
+  writeFile,
   createTemp,
   ensureDirectoryExists,
 };

lib/util/template.js

@@ -1,6 +1,6 @@
 const { template } = require('lodash');
-const { promisify } = require('util');
-const fs = require('fs');
+
+const { readFile, writeFile } = require('./fs');
 
 /**
  * Light wrapper over lodash templates making it safer to be used with javascript source code.
@@ -16,9 +16,6 @@ const jsSourceTemplate = (content, options) =>
     ...options,
   });
 
-const readFile = promisify(fs.readFile, { context: fs });
-const writeFile = promisify(fs.writeFile, { context: fs });
-
 /**
  * Compile the contents of specified (javascript) file as a lodash template
  *

test/unit/util/fs.js

@@ -4,6 +4,9 @@ const path = require('path');
 const { expect } = require('chai');
 const {
   stat,
+  readdir,
+  readFile,
+  writeFile,
   createTemp,
   ensureDirectoryExists,
 } = require('../../../lib/util/fs');
@@ -26,6 +29,51 @@ describe('FS functions', () => {
     });
   });
 
+  describe('readFile', async () => {
+    it('should be able to read from the given file path.', async () => {
+      const tmpPath = await createTemp();
+      const filePath = path.join(tmpPath, `${Date.now()}1.txt`);
+
+      fs.writeFileSync(filePath, 'Hello World!');
+
+      const contents = await readFile(filePath);
+
+      expect(contents.toString()).to.equal('Hello World!');
+    });
+  });
+
+  describe('writeFile', async () => {
+    it('should be able to write to the given file path.', async () => {
+      const tmpPath = await createTemp();
+      const filePath = path.join(tmpPath, `${Date.now()}2.txt`);
+
+      await writeFile(filePath, 'Foo Bar');
+
+      expect(fs.readFileSync(filePath).toString()).to.equal('Foo Bar');
+    });
+  });
+
+  describe('readdir', async () => {
+    it('should read a directory and return a list of files under it.', async () => {
+      const directory = await createTemp();
+
+      // Create files under the directory.
+      fs.writeFileSync(path.join(directory, 'testfile1.txt'), 'testfile1');
+      fs.writeFileSync(path.join(directory, 'testfile2.txt'), 'testfile2');
+      fs.writeFileSync(path.join(directory, 'testfile3.txt'), 'testfile3');
+      fs.writeFileSync(path.join(directory, 'testfile4.txt'), 'testfile4');
+
+      const result = await readdir(directory);
+
+      expect(result).to.deep.equal([
+        'testfile1.txt',
+        'testfile2.txt',
+        'testfile3.txt',
+        'testfile4.txt',
+      ]);
+    });
+  });
+
   describe('ensureDirectoryExists', () => {
     it('should resolve successfully if the directory already exists.', async () => {
       const directoryThatExists = await createTemp();