feat(dotenv-flow/config): add ability to configure `dotenv-flow/confi…

…g` via environment variables, relates #11

config.js

@@ -1,3 +1,5 @@
-(function() {
-  require('./lib/dotenv-flow').config()
-})()
+'use strict';
+
+const env_options = require('./lib/env-options');
+
+require('./lib/dotenv-flow').config(env_options());

lib/dotenv-flow.js

@@ -60,25 +60,27 @@ function getDotenvFilenames(cwd, node_env) {
  * @param {object} options - options for parsing `.env*` files
  * @param {string} [options.node_env=process.env.NODE_ENV] – environment to use (development/test/production/etc,.)
  * @param {string} [options.default_node_env] – the default environment value
- * @param {string} [options.cwd=process.cwd()] – path to `.env*` files directory
+ * @param {string} [options.path=process.cwd()] – path to `.env*` files directory
  * @param {string} [options.encoding="utf8"] – encoding of `.env*` files
  * @param {boolean} [options.purge_dotenv] – perform the {@link cleanupDotenvDefinedVars}
  * @return {object} with a `parsed` key containing the loaded content or an `error` key if it failed
-*/
+ */
 function config(options = {}) {
   const {
     node_env = (process.env.NODE_ENV || options.default_node_env),
-    cwd = process.cwd(),
     encoding = 'utf8',
     purge_dotenv = false
   } = options;
 
+  // `options.cwd` is here just for backward compatibility
+  const path = options.path || options.cwd || process.cwd();
+
   try {
     if (purge_dotenv) {
-      cleanupDotenvDefinedVars(cwd, encoding);
+      cleanupDotenvDefinedVars(path, encoding);
     }
 
-    const parsed = getDotenvFilenames(cwd, node_env)
+    const parsed = getDotenvFilenames(path, node_env)
       .reduce((parsed, path) => {
         const result = dotenv.config({ path, encoding });
 

lib/env-options.js

@@ -0,0 +1,25 @@
+'use strict';
+
+const ENV_OPTIONS_MAP = {
+  NODE_ENV: 'node_env',
+  DEFAULT_NODE_ENV: 'default_node_env',
+  DOTENV_FLOW_PATH: 'path',
+  DOTENV_FLOW_ENCODING: 'encoding',
+  DOTENV_FLOW_PURGE_DOTENV: 'purge_dotenv'
+};
+
+/**
+ * Get environment variable defined options for `dotenv-flow#config()`.
+ *
+ * @param {object} [env=process.env]
+ * @return {{node_env?: string, default_node_env?: string, path?: string, encoding?: string, purge_dotenv?: string}}
+ */
+module.exports = function env_options(env = process.env) {
+  return Object.keys(ENV_OPTIONS_MAP)
+    .reduce((options, key) => {
+      if (key in env) {
+        options[ ENV_OPTIONS_MAP[key] ] = env[key];
+      }
+      return options;
+    }, {});
+};

package.json

@@ -20,7 +20,8 @@
   },
   "main": "lib/dotenv-flow.js",
   "files": [
-    "lib/dotenv-flow.js"
+    "lib/env-options.js",
+    "config.js"
   ],
   "dependencies": {
     "dotenv": "^7.0.0"
@@ -32,7 +33,7 @@
     "tmp": "^0.1.0"
   },
   "scripts": {
-    "test": "mocha test/dotenv-flow.spec.js",
+    "test": "mocha test/*.spec.js",
     "changelog": "conventional-changelog -p angular -i CHANGELOG.md -s"
   },
   "author": "Dan Kerimdzhanov",

test/config-preload.spec.js

@@ -0,0 +1,88 @@
+'use strict';
+
+const path = require('path');
+const util = require('util');
+const execFile = util.promisify(require('child_process').execFile);
+const {expect} = require('chai');
+
+/**
+ * Get the path to a given fixture project.
+ *
+ * @param {string} name – fixture project name
+ * @return {string} – path to a fixture project
+ */
+function getFixtureProjectPath(name) {
+  return path.join(__dirname, 'fixtures', name);
+}
+
+/**
+ * Executes the preload helper script using the given fixture project as a working directory.
+ *
+ * @param {string} cwd – path to a fixture project
+ * @param {object} [env] – predefined environment variables
+ * @param {string[]} [args] – command line arguments
+ * @return {Promise<object>} – stdout parsed as a json
+ */
+async function execWithPreload(cwd, {env = {}, args = []} = {}) {
+  const {stdout} = await execFile(
+    process.argv[0], // ~= /usr/bin/node
+    [
+      '-r', '../config',
+      '-e', 'console.log(JSON.stringify(process.env));',
+      '--', ...args
+    ],
+    { cwd, env }
+  );
+
+  try {
+    return JSON.parse(stdout);
+  }
+  catch (e) {
+    console.error(e);
+    throw new Error(`Unable to parse the following as a JSON:\n${stdout}`);
+  }
+}
+
+describe('dotenv-flow/config', () => {
+  it('preloads `.env*` files defined environment variables', async () => {
+    const variables = await execWithPreload(getFixtureProjectPath('env'));
+
+    expect(variables)
+      .to.have.property('DEFAULT_ENV_VAR')
+      .that.is.equal('ok');
+  });
+
+  it('supports configuration via environment variables', async () => {
+    let variables = await execWithPreload(getFixtureProjectPath('env'), {
+      env: {
+        DEFAULT_NODE_ENV: 'development',
+        DOTENV_FLOW_PATH: getFixtureProjectPath('node-env')
+      }
+    });
+
+    expect(variables).to.include({
+      DEFAULT_NODE_ENV: 'development',
+      DEFAULT_ENV_VAR: 'ok',
+      DEVELOPMENT_ENV_VAR: 'ok',
+      DEVELOPMENT_ONLY_VAR: 'ok'
+    });
+
+    // --
+
+    variables = await execWithPreload(getFixtureProjectPath('env'), {
+      env: {
+        NODE_ENV: 'production',
+        DEFAULT_NODE_ENV: 'development',
+        DOTENV_FLOW_PATH: getFixtureProjectPath('node-env')
+      }
+    });
+
+    expect(variables).to.include({
+      NODE_ENV: 'production',
+      DEFAULT_NODE_ENV: 'development',
+      DEFAULT_ENV_VAR: 'ok',
+      PRODUCTION_ENV_VAR: 'ok',
+      PRODUCTION_ONLY_VAR: 'ok'
+    });
+  });
+});

test/env-options.spec.js

@@ -0,0 +1,38 @@
+'use strict';
+
+const {expect} = require('chai');
+const env_options = require('../lib/env-options');
+
+describe('env_options', () => {
+  it('maps related environment variables to options', () => {
+    expect(env_options({
+      NODE_ENV: 'production',
+      DEFAULT_NODE_ENV: 'development',
+      DOTENV_FLOW_PATH: '/path/to/project',
+      DOTENV_FLOW_ENCODING: 'latin1',
+      DOTENV_FLOW_PURGE_DOTENV: 'yes'
+    }))
+      .to.deep.equal({
+        node_env: 'production',
+        default_node_env: 'development',
+        path: '/path/to/project',
+        encoding: 'latin1',
+        purge_dotenv: 'yes'
+      });
+  });
+
+  it("doesn't include undefined environment variables", () => {
+    expect(env_options({
+      DEFAULT_NODE_ENV: 'development',
+      DOTENV_FLOW_ENCODING: 'latin1'
+    }))
+      .to.have.keys([
+        'default_node_env',
+        'encoding'
+      ]);
+  });
+
+  it('ignores unrelated environment variables', () => {
+    expect(env_options({ PATH: '/usr/local/bin' })).to.be.empty;
+  });
+});