feat: disallow description when no pattern exists (#4679)

This PR makes it so that adding a feature naming description when there
is no pattern is disallowed. It also changes the validation for feature
naming slightly so that it can return multiple errors at once.

src/lib/error/bad-data-error.ts

@@ -4,7 +4,7 @@ import getProp from 'lodash.get';
 import { ApiErrorSchema, UnleashError } from './unleash-error';
 
 type ValidationErrorDescription = {
-    description: string;
+    description?: string;
     message: string;
     path?: string;
 };

src/lib/features/feature-naming-pattern/feature-naming-validation.test.ts

@@ -60,6 +60,24 @@ describe('validate incoming feature naming data', () => {
             ).toMatchObject({ state: 'invalid' });
         }
     });
+
+    test('feature naming data with a non-empty example but an empty pattern is invalid', () => {
+        expect(
+            checkFeatureNamingData({
+                pattern: '',
+                example: 'example',
+            }),
+        ).toMatchObject({ state: 'invalid' });
+    });
+
+    test('feature naming data with a non-empty description but an empty pattern is invalid', () => {
+        expect(
+            checkFeatureNamingData({
+                pattern: '',
+                description: 'description',
+            }),
+        ).toMatchObject({ state: 'invalid' });
+    });
 });
 
 describe('validate feature flag names against a pattern', () => {

src/lib/features/feature-naming-pattern/feature-naming-validation.ts

@@ -4,25 +4,33 @@ const compileRegex = (pattern: string) => new RegExp(`^${pattern}$`);
 
 export const checkFeatureNamingData = (
     featureNaming?: IFeatureNaming,
-): { state: 'valid' } | { state: 'invalid'; reason: string } => {
+):
+    | { state: 'valid' }
+    | { state: 'invalid'; reasons: [string, ...string[]] } => {
     if (featureNaming) {
-        const { pattern, example } = featureNaming;
-        if (
-            pattern != null &&
-            example &&
-            !example.match(compileRegex(pattern))
-        ) {
-            return {
-                state: 'invalid',
-                reason: `You've provided a feature flag naming example ("${example}") that doesn't match your feature flag naming pattern ("${pattern}"). Please provide an example that matches your supplied pattern. Bear in mind that the pattern must match the whole example, as if it were surrounded by '^' and "$".`,
-            };
+        const { pattern, example, description } = featureNaming;
+        const errors: string[] = [];
+        if (pattern && example && !example.match(compileRegex(pattern))) {
+            errors.push(
+                `You've provided a feature flag naming example ("${example}") that doesn't match your feature flag naming pattern ("${pattern}"). Please provide an example that matches your supplied pattern. Bear in mind that the pattern must match the whole example, as if it were surrounded by '^' and "$".`,
+            );
         }
 
         if (!pattern && example) {
-            return {
-                state: 'invalid',
-                reason: "You've provided a feature flag naming example, but no feature flag naming pattern. You must specify a pattern to use an example.",
-            };
+            errors.push(
+                "You've provided a feature flag naming example, but no feature flag naming pattern. You must specify a pattern to use an example.",
+            );
+        }
+
+        if (!pattern && description) {
+            errors.push(
+                "You've provided a feature flag naming pattern description, but no feature flag naming pattern. You must have a pattern to use a description.",
+            );
+        }
+
+        const [first, ...rest] = errors;
+        if (first) {
+            return { state: 'invalid', reasons: [first, ...rest] };
         }
     }
 

src/lib/services/project-service.ts

@@ -176,7 +176,14 @@ export default class ProjectService {
         const validationResult = checkFeatureNamingData(featureNaming);
 
         if (validationResult.state === 'invalid') {
-            throw new BadDataError(validationResult.reason);
+            const [firstReason, ...remainingReasons] =
+                validationResult.reasons.map((message) => ({
+                    message,
+                }));
+            throw new BadDataError(
+                'The feature naming pattern data you provided was invalid.',
+                [firstReason, ...remainingReasons],
+            );
         }
 
         if (featureNaming.pattern && !featureNaming.example) {