config: added config.has()

packages/config/src/reader.test.ts

@@ -30,6 +30,7 @@ const DATA = {
   worstStrings: ['string1', 'string2', {}] as string[],
   nested: {
     one: 1,
+    null: null,
     string: 'string',
     strings: ['string1', 'string2'],
   },
@@ -39,6 +40,13 @@ const DATA = {
 function expectValidValues(config: ConfigReader) {
   expect(config.keys()).toEqual(Object.keys(DATA));
   expect(config.get('zero')).toBe(0);
+  expect(config.has('zero')).toBe(true);
+  expect(config.has('false')).toBe(true);
+  expect(config.has('null')).toBe(true);
+  expect(config.has('missing')).toBe(false);
+  expect(config.has('nested.one')).toBe(true);
+  expect(config.has('nested.missing')).toBe(false);
+  expect(config.has('nested.null')).toBe(true);
   expect(config.getNumber('zero')).toBe(0);
   expect(config.getNumber('one')).toBe(1);
   expect(config.getOptional('true')).toBe(true);
@@ -50,6 +58,7 @@ function expectValidValues(config: ConfigReader) {
   expect(config.getConfig('nested').getNumber('one')).toBe(1);
   expect(config.get('nested')).toEqual({
     one: 1,
+    null: null,
     string: 'string',
     strings: ['string1', 'string2'],
   });
@@ -144,14 +153,14 @@ describe('ConfigReader', () => {
   it('should throw on invalid keys', () => {
     const config = new ConfigReader({}, CTX);
 
-    expect(() => config.getString('.')).toThrow(/^Invalid config key/);
-    expect(() => config.getString('0')).toThrow(/^Invalid config key/);
-    expect(() => config.getString('(')).toThrow(/^Invalid config key/);
+    expect(() => config.has('.')).toThrow(/^Invalid config key/);
+    expect(() => config.get('0')).toThrow(/^Invalid config key/);
+    expect(() => config.getOptional('(')).toThrow(/^Invalid config key/);
     expect(() => config.getString('z-_')).toThrow(/^Invalid config key/);
-    expect(() => config.getString('-')).toThrow(/^Invalid config key/);
-    expect(() => config.getString('.a')).toThrow(/^Invalid config key/);
-    expect(() => config.getString('0.a')).toThrow(/^Invalid config key/);
-    expect(() => config.getString('0a')).toThrow(/^Invalid config key/);
+    expect(() => config.getOptionalString('-')).toThrow(/^Invalid config key/);
+    expect(() => config.getNumber('.a')).toThrow(/^Invalid config key/);
+    expect(() => config.getConfig('0.a')).toThrow(/^Invalid config key/);
+    expect(() => config.getOptionalConfig('0a')).toThrow(/^Invalid config key/);
     expect(() => config.getString('a.0a')).toThrow(/^Invalid config key/);
     expect(() => config.getString('a..a')).toThrow(/^Invalid config key/);
     expect(() => config.getString('a.')).toThrow(/^Invalid config key/);
@@ -308,6 +317,12 @@ describe('ConfigReader with fallback', () => {
     const config = new ConfigReader(a, CTX, new ConfigReader(b, CTX));
 
     expect(config.keys()).toEqual(['merged']);
+    expect(config.has('merged.x')).toBe(true);
+    expect(config.has('merged.y')).toBe(true);
+    expect(config.has('merged.w')).toBe(false);
+    expect(config.getConfig('merged').has('x')).toBe(true);
+    expect(config.getConfig('merged').has('y')).toBe(true);
+    expect(config.getConfig('merged').has('w')).toBe(false);
     expect(config.getConfig('merged').keys()).toEqual([
       'x',
       'z',

packages/config/src/reader.ts

@@ -71,6 +71,14 @@ export class ConfigReader implements Config {
     private readonly prefix: string = '',
   ) {}
 
+  has(key: string): boolean {
+    const value = this.readValue(key);
+    if (value !== undefined) {
+      return true;
+    }
+    return this.fallback?.has(key) ?? false;
+  }
+
   keys(): string[] {
     const localKeys = this.data ? Object.keys(this.data) : [];
     const fallbackKeys = this.fallback?.keys() ?? [];