feat(directive): add @purgeCache & @logCache directives

.eslintrc.js

@@ -12,10 +12,11 @@ module.exports = {
     'prettier',
   ],
   rules: {
-    "camelcase": "off",
-    "@typescript-eslint/camelcase": "off",
-    "@typescript-eslint/explicit-function-return-type": "off",
-    "@typescript-eslint/no-explicit-any": "off",
-    "@typescript-eslint/no-non-null-assertion": "off"
-  }
+    camelcase: 'off',
+    '@typescript-eslint/camelcase': 'off',
+    '@typescript-eslint/explicit-function-return-type': 'off',
+    '@typescript-eslint/no-explicit-any': 'off',
+    '@typescript-eslint/no-non-null-assertion': 'off',
+    '@typescript-eslint/no-unused-vars': "off",
+  },
 }

package.json

@@ -31,13 +31,17 @@
   "dependencies": {
     "apollo-cache-control": "^0.11.1",
     "apollo-server-caching": "^0.5.2",
-    "apollo-server-plugin-base": "^0.9.1"
+    "apollo-server-plugin-base": "^0.9.1",
+    "graphql": "^15.3.0",
+    "graphql-tools": "^6.0.14",
+    "lodash": "^4.17.19"
   },
   "devDependencies": {
     "@rollup/plugin-commonjs": "^14.0.0",
     "@rollup/plugin-node-resolve": "^8.4.0",
     "@rollup/plugin-typescript": "^5.0.2",
     "@types/graphql": "^14.5.0",
+    "@types/lodash": "^4.14.158",
     "@typescript-eslint/eslint-plugin": "^3.7.0",
     "@typescript-eslint/parser": "^3.7.0",
     "apollo-server-types": "^0.5.1",
@@ -52,7 +56,9 @@
     "typescript": "^3.9.7"
   },
   "peerDependencies": {
-    "graphql": "^0.12.0 || ^0.13.0 || ^14.0.0 || ^15.0.0"
+    "graphql": "^0.12.0 || ^0.13.0 || ^14.0.0 || ^15.0.0",
+    "graphql-tools": "^6.0.0",
+    "lodash": "^4.0.0"
   },
   "files": [
     "dist/**/*"

src/directives/logCache.ts

@@ -0,0 +1,37 @@
+import { defaultFieldResolver, GraphQLField } from 'graphql'
+import { SchemaDirectiveVisitor } from 'graphql-tools'
+
+import { CACHE_PREFIX } from '../enums'
+
+interface Params {
+  _type: string
+}
+
+export class LogCacheDirective extends SchemaDirectiveVisitor {
+  visitFieldDefinition(field: GraphQLField<any, any> & Params): void {
+    const { resolve = defaultFieldResolver } = field
+    field._type = this.args.type
+    field.resolve = async function (...args) {
+      const [root, _, { cacheKeys, redis }] = args
+      const result = await resolve.apply(this, args)
+
+      if (result && result.id && redis && cacheKeys && field._type) {
+        try {
+          let cacheType = field._type
+          switch (field._type) {
+            case 'Node':
+            case 'Response': {
+              cacheType = result.__type
+              break
+            }
+          }
+          cacheKeys.add(`${CACHE_PREFIX.KEYS}:${cacheType}:${result.id}`)
+        } catch (error) {
+          // TOOD: logger
+        }
+      }
+
+      return result
+    }
+  }
+}

src/directives/purgeCache.ts

@@ -0,0 +1,59 @@
+import { defaultFieldResolver, GraphQLField } from 'graphql'
+import { SchemaDirectiveVisitor } from 'graphql-tools'
+import { compact, replace, get } from 'lodash'
+
+import { CACHE_KEYWORD, CACHE_PREFIX } from '../enums'
+
+interface CacheSet {
+  id: string
+  type: string
+}
+
+const getCacheKeys = (customs: CacheSet[], fallback: CacheSet): string[] => {
+  if (customs && customs.length > 0) {
+    return compact(
+      customs.map((custom: CacheSet) => {
+        if (custom && custom.id && custom.type) {
+          return `${CACHE_PREFIX.KEYS}:${custom.type}:${custom.id}`
+        }
+      })
+    )
+  }
+
+  return [
+    `${CACHE_PREFIX.KEYS}:${replace(fallback.type, '!', '')}:${fallback.id}`,
+  ]
+}
+
+export class PurgeCacheDirective extends SchemaDirectiveVisitor {
+  visitFieldDefinition(field: GraphQLField<any, any>): void {
+    const { resolve = defaultFieldResolver } = field
+    field.resolve = async function (...args) {
+      const [root, _, { redis }, { returnType }] = args
+
+      const result = await resolve.apply(this, args)
+      if (result && result.id && redis && returnType) {
+        try {
+          const cache = get(result, CACHE_KEYWORD, [])
+          const keys = getCacheKeys(cache, {
+            id: result.id,
+            type: `${returnType}`,
+          })
+          keys.map(async (key: string) => {
+            const hashes = await redis.client.smembers(key)
+            hashes.map(async (hash: string) => {
+              await redis.client
+                .pipeline()
+                .del(`fqc:${hash}`)
+                .srem(key, hash)
+                .exec()
+            })
+          })
+        } catch (error) {
+          // TODO: logger
+        }
+      }
+      return result
+    }
+  }
+}

src/enums.ts

@@ -0,0 +1,7 @@
+// keyword notating for cache invalidation
+export const CACHE_KEYWORD = '__cache__'
+
+// redis cache for apq keys or resolver returned objects
+export const CACHE_PREFIX = {
+  KEYS: 'cache-keys',
+}

src/index.ts

@@ -1,3 +1,5 @@
-import responseCachePlugin from './ApolloServerPluginResponseCache'
+import responseCachePlugin from './plugins/responseCachePlugin'
+import { LogCacheDirective } from './directives/logCache'
+import { PurgeCacheDirective } from './directives/purgeCache'
 
-export { responseCachePlugin }
+export { responseCachePlugin, LogCacheDirective, PurgeCacheDirective }

tsconfig.json

@@ -1,4 +1,6 @@
 {
-  "compilerOptions": {},
+  "compilerOptions": {
+    "esModuleInterop": true
+  },
   "exclude": ["dist", "node_modules"]
 }