feat(#115): adds $eq directive

Author: joelgallant

app-config-default-extensions/index.js

@@ -17,6 +17,7 @@ module.exports = {
       unescape$Directives,
       tryDirective,
       ifDirective,
+      eqDirective,
       envDirective,
       extendsDirective,
       extendsSelfDirective,
@@ -33,6 +34,7 @@ module.exports = {
       unescape$Directives(),
       tryDirective(),
       ifDirective(),
+      eqDirective(),
       v1Compat(),
       envDirective(aliases, environmentOverride, environmentSourceNames),
       extendsDirective(),
@@ -54,6 +56,7 @@ module.exports = {
       unescape$Directives,
       tryDirective,
       ifDirective,
+      eqDirective,
       extendsDirective,
       extendsSelfDirective,
       overrideDirective,
@@ -63,6 +66,7 @@ module.exports = {
       unescape$Directives(),
       tryDirective(),
       ifDirective(),
+      eqDirective(),
       extendsDirective(),
       extendsSelfDirective(),
       overrideDirective(),

app-config-extensions/package.json

@@ -34,10 +34,12 @@
     "@app-config/extension-utils": "^2.1.7",
     "@app-config/logging": "^2.1.7",
     "@app-config/node": "^2.1.7",
-    "@app-config/utils": "^2.1.7"
+    "@app-config/utils": "^2.1.7",
+    "lodash.isequal": "4"
   },
   "devDependencies": {
-    "@app-config/test-utils": "^2.1.7"
+    "@app-config/test-utils": "^2.1.7",
+    "@types/lodash.isequal": "4"
   },
   "prettier": "@lcdev/prettier",
   "jest": {

app-config-extensions/src/index.test.ts

@@ -5,6 +5,7 @@ import { forKey } from '@app-config/extension-utils';
 import {
   tryDirective,
   ifDirective,
+  eqDirective,
   envDirective,
   extendsDirective,
   extendsSelfDirective,
@@ -176,6 +177,60 @@ describe('$if directive', () => {
   });
 });
 
+describe('$eq directive', () => {
+  it('returns true for empty', async () => {
+    const source = new LiteralSource({
+      $eq: [],
+    });
+
+    expect(await source.readToJSON([eqDirective()])).toBe(true);
+  });
+
+  it('returns true for two numbers', async () => {
+    const source = new LiteralSource({
+      $eq: [42, 42],
+    });
+
+    expect(await source.readToJSON([eqDirective()])).toBe(true);
+  });
+
+  it('returns false for two numbers', async () => {
+    const source = new LiteralSource({
+      $eq: [42, 44],
+    });
+
+    expect(await source.readToJSON([eqDirective()])).toBe(false);
+  });
+
+  it('returns true for two objects', async () => {
+    const source = new LiteralSource({
+      $eq: [{ a: true }, { a: true }],
+    });
+
+    expect(await source.readToJSON([eqDirective()])).toBe(true);
+  });
+
+  it('returns false for two objects', async () => {
+    const source = new LiteralSource({
+      $eq: [{ a: true }, { b: true }],
+    });
+
+    expect(await source.readToJSON([eqDirective()])).toBe(false);
+  });
+
+  it('parses before checking equality', async () => {
+    process.env.APP_CONFIG_ENV = 'test';
+    const source = new LiteralSource({
+      $eq: [
+        { $env: { default: { a: true } }},
+        { $env: { test: { a: true } }},
+      ],
+    });
+
+    expect(await source.readToJSON([eqDirective(), envDirective()])).toBe(true);
+  });
+});
+
 describe('$extends directive', () => {
   it('fails if file is missing', async () => {
     const source = new LiteralSource({

app-config-extensions/src/index.ts

@@ -1,4 +1,5 @@
 import { join, dirname, resolve, isAbsolute } from 'path';
+import isEqual from 'lodash.isequal';
 import {
   forKey,
   validateOptions,
@@ -95,6 +96,28 @@ export function ifDirective(): ParsingExtension {
   );
 }
 
+/** Checks if two values are equal */
+export function eqDirective(): ParsingExtension {
+  return forKey(
+    '$eq',
+    validateOptions(
+      (SchemaBuilder) => SchemaBuilder.arraySchema(SchemaBuilder.fromJsonSchema({})),
+      (values) => async (parse) => {
+        for (const a of values) {
+          for (const b of values) {
+            if (a === b) continue;
+            if (isEqual(a, b)) continue;
+
+            return parse(false, { shouldFlatten: true });
+          }
+        }
+
+        return parse(true, { shouldFlatten: true });
+      },
+    ),
+  );
+}
+
 /** Uses another file as overriding values, layering them on top of current file */
 export function overrideDirective(): ParsingExtension {
   return fileReferenceDirective('$override', { shouldOverride: true });

yarn.lock

@@ -2898,6 +2898,13 @@
     "@types/node" "*"
     "@types/webpack" "*"
 
+"@types/lodash.isequal@4":
+  version "4.5.5"
+  resolved "https://registry.yarnpkg.com/@types/lodash.isequal/-/lodash.isequal-4.5.5.tgz#4fed1b1b00bef79e305de0352d797e9bb816c8ff"
+  integrity sha512-4IKbinG7MGP131wRfceK6W4E/Qt3qssEFLF30LnJbjYiSfHGGRU/Io8YxXrZX109ir+iDETC8hw8QsDijukUVg==
+  dependencies:
+    "@types/lodash" "*"
+
 "@types/lodash.merge@4":
   version "4.6.6"
   resolved "https://registry.yarnpkg.com/@types/lodash.merge/-/lodash.merge-4.6.6.tgz#b84b403c1d31bc42d51772d1cd5557fa008cd3d6"
@@ -11202,6 +11209,11 @@ lodash.get@^4.4.2:
   resolved "https://registry.yarnpkg.com/lodash.get/-/lodash.get-4.4.2.tgz#2d177f652fa31e939b4438d5341499dfa3825e99"
   integrity sha1-LRd/ZS+jHpObRDjVNBSZ36OCXpk=
 
+lodash.isequal@4:
+  version "4.5.0"
+  resolved "https://registry.yarnpkg.com/lodash.isequal/-/lodash.isequal-4.5.0.tgz#415c4478f2bcc30120c22ce10ed3226f7d3e18e0"
+  integrity sha1-QVxEePK8wwEgwizhDtMib30+GOA=
+
 lodash.ismatch@^4.4.0:
   version "4.4.0"
   resolved "https://registry.yarnpkg.com/lodash.ismatch/-/lodash.ismatch-4.4.0.tgz#756cb5150ca3ba6f11085a78849645f188f85f37"