feat: adds $hidden directive

Author: joelgallant

app-config-default-extensions/index.js

@@ -18,6 +18,7 @@ module.exports = {
       tryDirective,
       ifDirective,
       eqDirective,
+      hiddenDirective,
       envDirective,
       envVarDirective,
       extendsDirective,
@@ -36,6 +37,7 @@ module.exports = {
       tryDirective(),
       ifDirective(),
       eqDirective(),
+      hiddenDirective(),
       v1Compat(),
       envDirective(aliases, environmentOverride, environmentSourceNames),
       envVarDirective(aliases, environmentOverride, environmentSourceNames),
@@ -59,6 +61,7 @@ module.exports = {
       tryDirective,
       ifDirective,
       eqDirective,
+      hiddenDirective,
       extendsDirective,
       extendsSelfDirective,
       overrideDirective,
@@ -69,6 +72,7 @@ module.exports = {
       tryDirective(),
       ifDirective(),
       eqDirective(),
+      hiddenDirective(),
       extendsDirective(),
       extendsSelfDirective(),
       overrideDirective(),

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

@@ -6,6 +6,7 @@ import {
   tryDirective,
   ifDirective,
   eqDirective,
+  hiddenDirective,
   envDirective,
   envVarDirective,
   extendsDirective,
@@ -229,6 +230,40 @@ describe('$eq directive', () => {
   });
 });
 
+describe('$hidden directive', () => {
+  it('doesnt include hidden', async () => {
+    const source = new LiteralSource({
+      $hidden: {},
+    });
+
+    expect(await source.readToJSON([hiddenDirective()])).toEqual({});
+  });
+
+  it('merges hidden', async () => {
+    const source = new LiteralSource({
+      $hidden: {},
+      foo: true,
+    });
+
+    expect(await source.readToJSON([hiddenDirective()])).toEqual({ foo: true });
+  });
+
+  it('references hidden property', async () => {
+    const source = new LiteralSource({
+      $hidden: {
+        foo: 42,
+      },
+      foo: {
+        $extendsSelf: '$hidden.foo',
+      },
+    });
+
+    expect(await source.readToJSON([hiddenDirective(), extendsSelfDirective()])).toEqual({
+      foo: 42,
+    });
+  });
+});
+
 describe('$extends directive', () => {
   it('fails if file is missing', async () => {
     const source = new LiteralSource({

app-config-extensions/src/index.ts

@@ -118,6 +118,13 @@ export function eqDirective(): ParsingExtension {
   );
 }
 
+/** Prpoerties that are removed, used by references */
+export function hiddenDirective(): ParsingExtension {
+  return forKey('$hidden', (value) => async (parse) => {
+    return parse({}, { shouldMerge: true });
+  });
+}
+
 /** Uses another file as overriding values, layering them on top of current file */
 export function overrideDirective(): ParsingExtension {
   return fileReferenceDirective('$override', { shouldOverride: true });