Add Payload Feature Flags plugin with custom endpoints and configurations

src/index.ts

@@ -0,0 +1,234 @@
+import type { Config, CollectionConfig, Field } from 'payload'
+
+import { customEndpointHandler } from './endpoints/customEndpointHandler.js'
+
+export type CollectionOverrides = Partial<
+  Omit<CollectionConfig, 'fields'>
+> & {
+  fields?: (args: { defaultFields: Field[] }) => Field[]
+}
+
+export type PayloadFeatureFlagsConfig = {
+  /**
+   * Enable/disable the plugin
+   * @default false
+   */
+  disabled?: boolean
+  /**
+   * Default value for new feature flags
+   * @default false
+   */
+  defaultValue?: boolean
+  /**
+   * Enable percentage-based rollouts
+   * @default true
+   */
+  enableRollouts?: boolean
+  /**
+   * Enable variant/experiment support (A/B testing)
+   * @default true
+   */
+  enableVariants?: boolean
+  /**
+   * Enable REST API endpoints for feature flags
+   * @default false
+   */
+  enableApi?: boolean
+  /**
+   * Override collection configuration
+   */
+  collectionOverrides?: CollectionOverrides
+}
+
+export const payloadFeatureFlags =
+  (pluginOptions: PayloadFeatureFlagsConfig = {}) =>
+  (config: Config): Config => {
+    const {
+      disabled = false,
+      defaultValue = false,
+      enableRollouts = true,
+      enableVariants = true,
+      enableApi = false,
+      collectionOverrides = {},
+    } = pluginOptions
+    
+    // Get collection slug from overrides or use default
+    const collectionSlug = collectionOverrides.slug || 'feature-flags'
+
+    if (!config.collections) {
+      config.collections = []
+    }
+
+    // Define default fields
+    const defaultFields: Field[] = [
+        {
+          name: 'name',
+          type: 'text',
+          required: true,
+          unique: true,
+          admin: {
+            description: 'Unique identifier for the feature flag',
+          },
+        },
+        {
+          name: 'description',
+          type: 'textarea',
+          admin: {
+            description: 'Describe what this feature flag controls',
+          },
+        },
+        {
+          name: 'enabled',
+          type: 'checkbox',
+          defaultValue: defaultValue,
+          required: true,
+          admin: {
+            description: 'Toggle this feature flag on or off',
+          },
+        },
+        ...(enableRollouts ? [
+          {
+            name: 'rolloutPercentage',
+            type: 'number',
+            min: 0,
+            max: 100,
+            defaultValue: 100,
+            admin: {
+              description: 'Percentage of users who will see this feature (0-100)',
+              condition: (data: any) => data?.enabled === true,
+            },
+          },
+        ] : []),
+        ...(enableVariants ? [
+          {
+            name: 'variants',
+            type: 'array',
+            admin: {
+              description: 'Define variants for A/B testing',
+              condition: (data: any) => data?.enabled === true,
+            },
+            fields: [
+              {
+                name: 'name',
+                type: 'text',
+                required: true,
+                admin: {
+                  description: 'Variant identifier (e.g., control, variant-a)',
+                },
+              },
+              {
+                name: 'weight',
+                type: 'number',
+                min: 0,
+                max: 100,
+                required: true,
+                admin: {
+                  description: 'Weight for this variant (all weights should sum to 100)',
+                },
+              },
+              {
+                name: 'metadata',
+                type: 'json',
+                admin: {
+                  description: 'Additional data for this variant',
+                },
+              },
+            ],
+          },
+        ] : []),
+        {
+          name: 'tags',
+          type: 'array',
+          fields: [
+            {
+              name: 'tag',
+              type: 'text',
+            },
+          ],
+          admin: {
+            description: 'Tags for organizing feature flags',
+          },
+        },
+        {
+          name: 'metadata',
+          type: 'json',
+          admin: {
+            description: 'Additional metadata for this feature flag',
+          },
+        },
+    ]
+
+    // Apply field overrides if provided
+    const fields = collectionOverrides.fields 
+      ? collectionOverrides.fields({ defaultFields })
+      : defaultFields
+
+    // Extract field overrides from collectionOverrides
+    const { fields: _fieldsOverride, ...otherOverrides } = collectionOverrides
+
+    // Create the feature flags collection with overrides
+    const featureFlagsCollection: CollectionConfig = {
+      slug: collectionSlug,
+      admin: {
+        useAsTitle: 'name',
+        group: 'Configuration',
+        description: 'Manage feature flags for your application',
+        ...(otherOverrides.admin || {}),
+      },
+      fields,
+      // Apply any other collection overrides
+      ...otherOverrides,
+    }
+
+    config.collections.push(featureFlagsCollection)
+
+    /**
+     * If the plugin is disabled, we still want to keep the collection
+     * so the database schema is consistent which is important for migrations.
+     */
+    if (disabled) {
+      return config
+    }
+
+    if (!config.endpoints) {
+      config.endpoints = []
+    }
+
+    if (!config.admin) {
+      config.admin = {}
+    }
+
+    if (!config.admin.components) {
+      config.admin.components = {}
+    }
+
+    if (!config.admin.components.beforeDashboard) {
+      config.admin.components.beforeDashboard = []
+    }
+
+    config.admin.components.beforeDashboard.push(
+      `payload-feature-flags/client#BeforeDashboardClient`,
+    )
+    config.admin.components.beforeDashboard.push(
+      `payload-feature-flags/rsc#BeforeDashboardServer`,
+    )
+
+    // Add API endpoints if enabled
+    if (enableApi) {
+      // Add API endpoint for fetching feature flags
+      config.endpoints.push({
+        handler: customEndpointHandler(collectionSlug),
+        method: 'get',
+        path: '/feature-flags',
+      })
+
+      // Add endpoint for checking a specific feature flag
+      config.endpoints.push({
+        handler: customEndpointHandler(collectionSlug),
+        method: 'get',
+        path: '/feature-flags/:flag',
+      })
+    }
+
+    return config
+  }