Merge pull request #15423 from SayakMukhopadhyay/fix-15422

fix: environment variable substitution in config doesn't work with boolean values

.changeset/tidy-flies-cheer.md

@@ -0,0 +1,7 @@
+---
+'@backstage/config': patch
+---
+
+Adds the ability to coerce values to their boolean representatives.
+Values such as `"true"` `1` `on` and `y` will become `true` when using `getBoolean` and the opposites `false`.
+This happens particularly when such parameters are used with environmental substitution as environment variables are always strings.

packages/config/src/reader.test.ts

@@ -22,6 +22,15 @@ const DATA = {
   one: 1,
   true: true,
   false: false,
+  yes: 'yes',
+  no: 'no',
+  y: 'y',
+  n: 'n',
+  on: 'on',
+  off: 'off',
+  zeroString: '0',
+  oneString: '1',
+  stringFalse: 'false',
   null: null,
   string: 'string',
   emptyString: '',
@@ -53,6 +62,17 @@ function expectValidValues(config: ConfigReader) {
   expect(config.getOptional('true')).toBe(true);
   expect(config.getBoolean('true')).toBe(true);
   expect(config.getBoolean('false')).toBe(false);
+  expect(config.getBoolean('stringFalse')).toBe(false);
+  expect(config.getBoolean('zero')).toBe(false);
+  expect(config.getBoolean('one')).toBe(true);
+  expect(config.getBoolean('zeroString')).toBe(false);
+  expect(config.getBoolean('oneString')).toBe(true);
+  expect(config.getBoolean('yes')).toBe(true);
+  expect(config.getBoolean('no')).toBe(false);
+  expect(config.getBoolean('y')).toBe(true);
+  expect(config.getBoolean('n')).toBe(false);
+  expect(config.getBoolean('on')).toBe(true);
+  expect(config.getBoolean('off')).toBe(false);
   expect(config.getString('string')).toBe('string');
   expect(config.get('strings')).toEqual(['string1', 'string2']);
   expect(config.getStringArray('strings')).toEqual(['string1', 'string2']);
@@ -86,7 +106,7 @@ function expectValidValues(config: ConfigReader) {
 
 function expectInvalidValues(config: ConfigReader) {
   expect(() => config.getBoolean('string')).toThrow(
-    "Invalid type in config for key 'string' in 'ctx', got string, wanted boolean",
+    "Unable to convert config value for key 'string' in 'ctx' to a boolean",
   );
   expect(() => config.getNumber('string')).toThrow(
     "Unable to convert config value for key 'string' in 'ctx' to a number",

packages/config/src/reader.ts

@@ -280,10 +280,25 @@ export class ConfigReader implements Config {
 
   /** {@inheritdoc Config.getOptionalBoolean} */
   getOptionalBoolean(key: string): boolean | undefined {
-    return this.readConfigValue(
+    const value = this.readConfigValue<string | number | boolean>(
       key,
-      value => typeof value === 'boolean' || { expected: 'boolean' },
+      val =>
+        typeof val === 'boolean' ||
+        typeof val === 'number' ||
+        typeof val === 'string' || { expected: 'boolean' },
     );
+    if (typeof value === 'boolean' || value === undefined) {
+      return value;
+    }
+    const valueString = String(value).trim();
+
+    if (/^(?:y|yes|true|1|on)$/i.test(valueString)) {
+      return true;
+    }
+    if (/^(?:n|no|false|0|off)$/i.test(valueString)) {
+      return false;
+    }
+    throw new Error(errors.convert(this.fullKey(key), this.context, 'boolean'));
   }
 
   /** {@inheritdoc Config.getString} */