feat(build): add lb-env script to set up env vars

Author: raymondfeng

packages/build/bin/run-env.js

@@ -0,0 +1,90 @@
+#!/usr/bin/env node
+// Copyright IBM Corp. 2017,2018. All Rights Reserved.
+// Node module: @loopback/build
+// This file is licensed under the MIT License.
+// License text available at https://opensource.org/licenses/MIT
+
+/*
+========
+
+Usage:
+  node ./bin/run-env [VAR1=<val1> VAR2=<var2> --file <env.json>] command [arguments...]
+
+The script will scan all arguments matching `VAR=val` and set them into
+environment variables to be inherited by the command.
+
+Then the provided command is executed with the optional arguments.
+
+Example usage:
+
+  node ./bin/run-env DEBUG=loopback:* npm test
+
+========
+*/
+
+'use strict';
+
+const debug = require('debug')('loopback:build:env');
+const util = require('util');
+const fs = require('fs-extra');
+
+function loadEnvFile(f) {
+  debug('Loading environment variables from %s', f);
+  return fs.readJsonSync(f);
+}
+
+function run(argv, options) {
+  const utils = require('./utils');
+
+  let args = argv.slice(2);
+  const envVars = {};
+  let files = [];
+  let i;
+  for (i = 0; i < args.length; i++) {
+    const arg = args[i];
+    if (arg === '--file') {
+      const json = loadEnvFile(args[++i]);
+      Object.assign(envVars, json);
+      continue;
+    }
+    const index = arg.indexOf('=');
+    if (index === -1) {
+      break;
+    } else {
+      const key = arg.substring(0, index).trim();
+      const val = arg.substring(index + 1).trim();
+      envVars[key] = val;
+    }
+  }
+
+  for (const p in envVars) {
+    debug('Setting environment variable: %s=%s', p, envVars[p]);
+    process.env[p] = envVars[p];
+  }
+
+  args = args.slice(i);
+  let command = args.shift();
+
+  if (!command) {
+    // Command is not present
+    const msg = util.format(
+      'Usage: %s command <options-and-args>',
+      argv.join(' ')
+    );
+    process.exitCode = 1;
+    return msg;
+  }
+
+  if (options === true || (options && options.dryRun)) {
+    const envArgs = [];
+    for (const p in envVars) {
+      envArgs.push(`${p}=${envVars[p]}`);
+    }
+    envArgs.push(command);
+    command = envArgs.join(' ');
+  }
+  return utils.runShell(command, args, options);
+}
+
+module.exports = run;
+if (require.main === module) run(process.argv);

packages/build/package.json

@@ -35,7 +35,8 @@
     "lb-nyc": "./bin/run-nyc.js",
     "lb-dist": "./bin/select-dist.js",
     "lb-apidocs": "./bin/generate-apidocs.js",
-    "lb-clean": "./bin/run-clean.js"
+    "lb-clean": "./bin/run-clean.js",
+    "lb-env": "./bin/run-env.js"
   },
   "scripts": {
     "lint": "npm run prettier:check",

packages/build/test/fixtures/env.json

@@ -0,0 +1,4 @@
+{
+  "VAR1": 1,
+  "VAR2": 2
+}

packages/build/test/integration/scripts.test.js

@@ -294,4 +294,63 @@ describe('build', function() {
     );
     assert(command.indexOf('rm -rf ./dist') !== -1);
   });
+
+  it('sets env vars with run-env', () => {
+    var run = require('../../bin/run-env');
+    var command = run(
+      [
+        'node',
+        'bin/run-env',
+        'VAR1=1',
+        'VAR2=a',
+        'node',
+        '-e',
+        'console.log(process.env.VAR1);',
+      ],
+      true
+    );
+    assert.equal(
+      command,
+      'VAR1=1 VAR2=a node "-e" "console.log(process.env.VAR1);"'
+    );
+  });
+
+  it('sets env vars from files with run-env', () => {
+    var run = require('../../bin/run-env');
+    const envFile = path.join(__dirname, '../fixtures/env.json');
+    var command = run(
+      [
+        'node',
+        'bin/run-env',
+        '--file',
+        envFile,
+        'node',
+        '-e',
+        'console.log(process.env.VAR1);',
+      ],
+      true
+    );
+    assert.equal(
+      command,
+      'VAR1=1 VAR2=2 node "-e" "console.log(process.env.VAR1);"'
+    );
+  });
+
+  it('allows no env vars with run-env', () => {
+    var run = require('../../bin/run-env');
+    var command = run(
+      ['node', 'bin/run-env', 'node', '-e', 'console.log(process.env.VAR1);'],
+      true
+    );
+    assert.equal(command, 'node "-e" "console.log(process.env.VAR1);"');
+  });
+
+  it('reports error if no command is provided with run-env', () => {
+    var run = require('../../bin/run-env');
+    var command = run(['node', 'bin/run-env', 'VAR1=1'], true);
+    assert.equal(
+      command,
+      'Usage: node bin/run-env VAR1=1 command <options-and-args>'
+    );
+  });
 });