feat(config): enable configurability with a config file

Introduce a new `ace-config` package:
- exposes a `paths` object storing the system paths (log, config, data, etc)
- exposes the config stored in the config file in the `config` object
- exposes constants in the `constants` object

The config file will be stored in the user's OS-specific configuration directory

Fixes #63, Fixes #77

packages/ace-config/package.json

@@ -0,0 +1,27 @@
+{
+  "name": "@daisy/ace-config",
+  "version": "0.0.1",
+  "description": "Config utilities for Ace",
+  "author": {
+    "name": "DAISY developers",
+    "organization": "DAISY Consortium",
+    "url": "http://www.daisy.org/"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/daisy/ace"
+  },
+  "bugs": {
+    "url": "https://github.com/daisy/ace/issues"
+  },
+  "license": "MIT",
+  "main": "lib/index.js",
+  "dependencies": {
+    "conf": "^1.3.1",
+    "env-paths": "^1.0.0",
+    "lodash.mergewith": "^4.6.0"
+  },
+  "publishConfig": {
+    "access": "public"
+  }
+}

packages/ace-config/src/__tests__/config-store.test.js

@@ -0,0 +1,60 @@
+'use strict';
+
+const ConfigStore = require('../config-store');
+const tmp = require('tmp');
+
+tmp.setGracefulCleanup();
+
+let conf;
+const fixture = {
+  a: 1,
+  b: [2, 2],
+  c: { x: 3, y: 3 },
+};
+
+beforeEach(() => {
+  conf = new ConfigStore({ cwd: tmp.dirSync({ unsafeCleanup: true }).name });
+});
+
+test('config store is defined', () => {
+  expect(ConfigStore).toBeDefined();
+});
+
+test('.get 2-args to work as in parent', () => {
+  expect(conf.get('foo')).not.toBeDefined();
+  expect(conf.get('foo', 'bar')).toBe('bar');
+  conf.set('foo', fixture);
+  expect(conf.get('foo')).toEqual(fixture);
+});
+
+test('.get to ignore null or false merge mode', () => {
+  conf.set('foo', fixture);
+  expect(conf.get('foo', { d: 4 }, null)).toEqual(fixture);
+  expect(conf.get('foo', { d: 4 }, false)).toEqual(fixture);
+});
+
+test('.get merge mode to merge the defaults', () => {
+  conf.set('foo', fixture);
+  expect(conf.get('foo', { c: { z: 3 } }, true)).toEqual({
+    a: 1,
+    b: [2, 2],
+    c: { x: 3, y: 3, z: 3 },
+  });
+});
+
+test('.get merge mode override the defaults', () => {
+  conf.set('foo', fixture);
+  expect(conf.get('foo', { a: 'foo' }, true)).toEqual(fixture);
+  expect(conf.get('foo', { c: { x: 'foo' } }, true)).toEqual(fixture);
+});
+
+test('.get merge mode ignores non-object defaults', () => {
+  conf.set('foo', fixture);
+  expect(conf.get('foo', 'foo', true)).toEqual(fixture);
+  expect(conf.get('foo', null, true)).toEqual(fixture);
+});
+
+test('.get merge mode concatenates arrays', () => {
+  conf.set('foo', fixture);
+  expect(conf.get('foo', { b: ['x'] }, true)).toMatchObject({ b: ['x', 2, 2] });
+});

packages/ace-config/src/__tests__/index.test.js

@@ -0,0 +1,29 @@
+'use strict';
+
+const path = require('path');
+const { config, paths, constants } = require('..');
+
+test('config store is defined', () => {
+  expect(config).toBeDefined();
+});
+
+test('config file default name', () => {
+  expect(path.basename(config.path)).toEqual('config.json');
+  expect(path.basename(path.dirname(config.path))).toEqual('DAISY Ace');
+});
+
+test('paths are defined', () => {
+  expect(paths).toBeDefined();
+  expect(paths.config).toBeDefined();
+  expect(paths.data).toBeDefined();
+  expect(paths.log).toBeDefined();
+  expect(paths.temp).toBeDefined();
+});
+
+test('constants are defined', () => {
+  expect(constants).toBeDefined();
+});
+
+test('constants are as in constants.json', () => {
+  expect(constants.dirname).toBe('DAISY Ace');
+});

packages/ace-config/src/config-store.js

@@ -0,0 +1,20 @@
+'use strict';
+
+const Conf = require('conf');
+const merge = require('lodash.mergewith');
+
+class ConfigStore extends Conf {
+
+  get(key, defaultValue, mergeMode) {
+    if (mergeMode && typeof defaultValue === 'object') {
+      return merge({}, defaultValue, super.get(key), (obj, val) => {
+        if (Array.isArray(obj)) {
+          return obj.concat(val);
+        }
+      });
+    }
+    return super.get(key, defaultValue);
+  }
+}
+
+module.exports = ConfigStore;

packages/ace-config/src/constants.json

@@ -0,0 +1,3 @@
+{
+  "dirname": "DAISY Ace"
+}

packages/ace-config/src/index.js

@@ -0,0 +1,17 @@
+'use strict';
+
+const envPaths = require('env-paths');
+const constants = require('./constants');
+const ConfigStore = require('./config-store');
+
+const paths = envPaths(constants.dirname, { suffix: null });
+
+const config = new ConfigStore({
+  cwd: paths.config,
+});
+
+module.exports = {
+  config,
+  constants: Object.freeze(constants),
+  paths,
+};

yarn.lock

@@ -1215,6 +1215,16 @@ [email protected], concat-stream@^1.4.10, concat-stream@^1.5.0, concat-stream@
     readable-stream "^2.2.2"
     typedarray "^0.0.6"
 
+conf@^1.3.1:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/conf/-/conf-1.3.1.tgz#829a82b081bb355129992333be1598f797a56f58"
+  dependencies:
+    dot-prop "^4.1.0"
+    env-paths "^1.0.0"
+    make-dir "^1.0.0"
+    pkg-up "^2.0.0"
+    write-file-atomic "^2.3.0"
+
 configstore@^1.0.0, configstore@^1.2.0:
   version "1.4.0"
   resolved "https://registry.yarnpkg.com/configstore/-/configstore-1.4.0.tgz#c35781d0501d268c25c54b8b17f6240e8a4fb021"
@@ -1649,6 +1659,12 @@ dot-prop@^3.0.0:
   dependencies:
     is-obj "^1.0.0"
 
+dot-prop@^4.1.0:
+  version "4.2.0"
+  resolved "https://registry.yarnpkg.com/dot-prop/-/dot-prop-4.2.0.tgz#1f19e0c2e1aa0e32797c49799f2837ac6af69c57"
+  dependencies:
+    is-obj "^1.0.0"
+
 duplexer2@^0.1.4:
   version "0.1.4"
   resolved "https://registry.yarnpkg.com/duplexer2/-/duplexer2-0.1.4.tgz#8b12dab878c0d69e3e7891051662a32fc6bddcc1"
@@ -3685,7 +3701,7 @@ lodash.defaultsdeep@^4.3.1:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/lodash.defaultsdeep/-/lodash.defaultsdeep-4.6.0.tgz#bec1024f85b1bd96cbea405b23c14ad6443a6f81"
 
-lodash.mergewith@^4.3.1:
+lodash.mergewith@^4.3.1, lodash.mergewith@^4.6.0:
   version "4.6.0"
   resolved "https://registry.yarnpkg.com/lodash.mergewith/-/lodash.mergewith-4.6.0.tgz#150cf0a16791f5903b8891eab154609274bdea55"
 
@@ -4382,6 +4398,12 @@ pkg-dir@^1.0.0:
   dependencies:
     find-up "^1.0.0"
 
+pkg-up@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/pkg-up/-/pkg-up-2.0.0.tgz#c819ac728059a461cab1c3889a2be3c49a004d7f"
+  dependencies:
+    find-up "^2.1.0"
+
 pluralize@^1.2.1:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/pluralize/-/pluralize-1.2.1.tgz#d1a21483fd22bb41e58a12fa3421823140897c45"