Loads extra arguments from the yarnrc files

src/cli/index.js

@@ -8,6 +8,7 @@ import * as network from '../util/network.js';
 import {MessageError} from '../errors.js';
 import aliases from './aliases.js';
 import Config from '../config.js';
+import {getRcArgs} from '../rc.js';
 import {camelCase} from '../util/misc.js';
 
 const chalk = require('chalk');
@@ -167,7 +168,7 @@ if (ARGS_THAT_SHARE_NAMES_WITH_OPTIONS.indexOf(commandName) >= 0 && args[0] ===
   args.shift();
 }
 
-commander.parse(startArgs.concat(args));
+commander.parse(getRcArgs().concat(startArgs).concat(args));
 commander.args = commander.args.concat(endArgs);
 
 if (command) {

src/rc.js

@@ -0,0 +1,101 @@
+import { readFileSync } from 'fs';
+import rc from 'rc';
+
+import parse from './lockfile/parse.js';
+
+// Keys that will be propagated into the command line as arguments
+const ARG_KEYS = [
+    'production',
+
+    'offline',
+    'prefer-offline',
+    'proxy',
+    'https-proxy',
+    'network-concurrency',
+
+    'strict-semver',
+    'ignore-engines',
+    'ignore-optional',
+    'ignore-platform',
+    'ignore-scripts',
+    'skip-integrity-check',
+
+    'no-lockfile',
+    'pure-lockfile',
+    'frozen-lockfile',
+
+    'no-bin-links',
+    'link-duplicates',
+    'flat',
+
+    'cache-folder',
+    'modules-folder',
+    'global-folder',
+
+    'mutex',
+
+    'no-emoji',
+    'har',
+];
+
+// Keys that will get resolved relative to the path of the rc file they belong to
+const PATH_KEYS = [
+    'cache-folder',
+    'global-folder',
+    'modules-folder',
+];
+
+// Map old keys to more recent ones
+const ALIAS_KEYS = {
+    //'yarn-offline-mirror': 'mirror-path'
+    //'skip-integrity-check': 'ignore-integrity'
+};
+
+const buildRcConf = () => rc('yarn', {}, [], fileText => {
+    const values = parse(fileText, null);
+
+    for (let key of Object.keys(ALIAS_KEYS)) {
+        if (Object.prototype.hasOwnProperty.call(values, key)) {
+            values[ALIAS_KEYS[key]] = values[key];
+        }
+    }
+
+    for (let key of PATH_KEYS) {
+        if (Object.prototype.hasOwnProperty.call(values, key)) {
+            values[key] = resolve(dirname(filePath), values[key]);
+        }
+    }
+
+    return values;
+});
+
+export function getRcConf() {
+    if (!getRcConf.cache)
+        getRcConf.cache = buildRcConf();
+
+    return getRcConf.cache;
+}
+
+const buildRcArgs = () => ARG_KEYS.reduce((args, key) => {
+    const value = getRcConf()[key];
+
+    if (typeof value === 'string') {
+        args = args.concat([ `--${key}`, value ]);
+    } else if (typeof value === 'boolean') {
+        args = args.concat([ `--${key}` ]);
+    }
+
+    return args;
+}, []);
+
+export function getRcArgs() {
+    if (!getRcArgs.cache)
+        getRcArgs.cache = buildRcArgs();
+
+    return getRcArgs.cache;
+}
+
+export function clearRcCache() {
+    getRcConf.cache = null;
+    getRcArgs.cache = null;
+}