feat(cacheModifier): Added cache modifier function, bumped dependencies

BowlingX · Mar 4, 2019 · 4e24acc · 4e24acc
1 parent a8ab447
commit 4e24acc
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Showing 6 changed files with 91 additions and 80 deletions.
diff --git a/README.md b/README.md
@@ -111,6 +111,10 @@ interface Cache<K, V> {
 
 Javascript's `Map` implements this interface, so you can use that as default.
 
+### Customize the cache key
+
+You can pass a function as second argument (`type CacheKeyModifier = (?string, ?Object) => ?string`) on  `proxyCacheLink` and `proxyCacheMiddleware` that allows you to modify the key before saving. This is useful if your queries depend on a global context. e.g. a http header that modifies the result independend of the query parameters (e.g. `Accept-Language`)
+
 ### TODO
 
 - Add support for batch queries

diff --git a/package.json b/package.json
@@ -26,10 +26,11 @@
     "eslint-config-google": "^0.11.0",
     "eslint-plugin-flowtype": "^3.2.1",
     "eslint-plugin-import": "^2.14.0",
-    "flow-bin": "^0.90.0",
+    "flow-bin": "^0.94.0",
     "flow-copy-source": "^2.0.2",
     "rimraf": "^2.6.3",
-    "semantic-release": "^15.13.3"
+    "semantic-release": "^15.13.3",
+    "babel-eslint": "^10.0.1"
   },
   "scripts": {
     "prepare": "yarn run build:clean && yarn run build:lib && yarn run build:flow",
@@ -52,8 +53,7 @@
     "@babel/polyfill": "^7.2.5",
     "apollo-link": "^1.2.6",
     "apollo-utilities": "^1.0.27",
-    "babel-eslint": "^10.0.1",
-    "graphql": "^14.0.2",
+    "graphql": "^14.1.1",
     "http-proxy-middleware": "^0.19.1",
     "lodash": "^4.17.11"
   }

diff --git a/src/proxyCacheLink.js b/src/proxyCacheLink.js
@@ -6,9 +6,9 @@ import {
 } from 'apollo-link'
 import { hasDirectives } from 'apollo-utilities'
 import { calculateArguments, didTimeout, DIRECTIVE, removeCacheDirective } from './utils'
-import type { Cache } from './utils'
+import type { Cache, CacheKeyModifier } from './utils'
 
-export const proxyCacheLink = (queryCache: Cache<String, Object>) => {
+export const proxyCacheLink = (queryCache: Cache<string, Object>, cacheKeyModifier: CacheKeyModifier) => {
   return new class NodeCacheLink extends ApolloLink {
     request(operation: Object, forward): Observable<any> {
       const directives = 'directive @cache on QUERY'
@@ -23,7 +23,7 @@ export const proxyCacheLink = (queryCache: Cache<String, Object>) => {
       const server = removeCacheDirective(operation.query)
       const { query } = operation
       if (server) operation.query = server
-      const { id, timeout } = calculateArguments(query, operation.variables)
+      const { id, timeout } = calculateArguments(query, operation.variables, cacheKeyModifier)
 
       const possibleData = queryCache.get(id)
 

diff --git a/src/proxyCacheMiddleware.js b/src/proxyCacheMiddleware.js
@@ -5,78 +5,79 @@ import { parse } from 'graphql'
 import { print } from 'graphql/language/printer'
 import { hasDirectives } from 'apollo-utilities'
 import { calculateArguments, didTimeout, DIRECTIVE, removeCacheDirective } from './utils'
-import type { Cache } from './utils'
+import type { Cache, CacheKeyModifier } from './utils'
 
 const CACHE_HEADER = 'X-Proxy-Cached'
 
 export const proxyCacheMiddleware =
-    (queryCache: Cache<String, Object>) => (app: Object, endpoint: string, proxyConfig: Object) => {
-      app.use(endpoint, (req, response, next) => {
-        if (!req.body) {
+    (queryCache: Cache<string, Object>, cacheKeyModifier: CacheKeyModifier) =>
+      (app: Object, endpoint: string, proxyConfig: Object) => {
+        app.use(endpoint, (req, response, next) => {
+          if (!req.body) {
       console.warn('[skip] proxy-cache-middleware, request.body is not populated. Please add "body-parser" middleware (or similar).') // eslint-disable-line
-          return next()
-        }
-        if (!req.body.query) {
-          return next()
-        }
-        const doc = parse(req.body.query)
-        const isCache = hasDirectives([ DIRECTIVE ], doc)
+            return next()
+          }
+          if (!req.body.query) {
+            return next()
+          }
+          const doc = parse(req.body.query)
+          const isCache = hasDirectives([ DIRECTIVE ], doc)
 
-        // we remove the @cache directive if it exists
-        if (isCache) {
-          const nextQuery = removeCacheDirective(doc)
-          const { id, timeout } = calculateArguments(doc, req.body.variables)
-          const possibleData = queryCache.get(id)
-          if (possibleData) {
-            const { data, time } = possibleData
-            if (didTimeout(timeout, time)) {
-              queryCache.delete(id)
-            } else {
-              response.set(CACHE_HEADER, 'true')
-              return response.json({ data })
+          // we remove the @cache directive if it exists
+          if (isCache) {
+            const nextQuery = removeCacheDirective(doc)
+            const { id, timeout } = calculateArguments(doc, req.body.variables, cacheKeyModifier)
+            const possibleData = queryCache.get(id)
+            if (possibleData) {
+              const { data, time } = possibleData
+              if (didTimeout(timeout, time)) {
+                queryCache.delete(id)
+              } else {
+                response.set(CACHE_HEADER, 'true')
+                return response.json({ data })
+              }
             }
+            req._hasCache = { id, timeout }
+            // could this be piped here (with req.pipe)
+            req.body = { ...req.body, query: print(nextQuery) }
           }
-          req._hasCache = { id, timeout }
-          // could this be piped here (with req.pipe)
-          req.body = { ...req.body, query: print(nextQuery) }
-        }
-        next()
-      })
+          next()
+        })
 
-      app.use(endpoint, proxy({
-        ...proxyConfig,
-        onProxyReq: (proxyReq, req, res) => {
+        app.use(endpoint, proxy({
+          ...proxyConfig,
+          onProxyReq: (proxyReq, req, res) => {
           // We have to rewrite the request body due to body-parser's removal of the content.
-          const data = JSON.stringify(req.body)
-          proxyReq.setHeader('Content-Length', Buffer.byteLength(data))
-          proxyReq.write(data)
-          if (proxyConfig.onProxyReq) {
-            proxyConfig.onProxyReq(proxyReq, req, res)
-          }
-        },
-        onProxyRes: (proxyRes, req, res) => {
-          if (req._hasCache) {
-            const { id } = req._hasCache
-            // Save data into cache
-            let body = new Buffer('')
-            proxyRes.on('data', function(data) {
-              body = Buffer.concat([ body, data ])
-            })
-            proxyRes.on('end', function() {
-              try {
-                const response = JSON.parse(body.toString())
-                // We don't cache when there are any errors in the response
-                if (!response.errors && response.data) {
-                  queryCache.set(id, { data: response.data, time: Number(new Date()) })
-                }
-              } catch (e) {
+            const data = JSON.stringify(req.body)
+            proxyReq.setHeader('Content-Length', Buffer.byteLength(data))
+            proxyReq.write(data)
+            if (proxyConfig.onProxyReq) {
+              proxyConfig.onProxyReq(proxyReq, req, res)
+            }
+          },
+          onProxyRes: (proxyRes, req, res) => {
+            if (req._hasCache) {
+              const { id } = req._hasCache
+              // Save data into cache
+              let body = new Buffer('')
+              proxyRes.on('data', function(data) {
+                body = Buffer.concat([ body, data ])
+              })
+              proxyRes.on('end', function() {
+                try {
+                  const response = JSON.parse(body.toString())
+                  // We don't cache when there are any errors in the response
+                  if (!response.errors && response.data) {
+                    queryCache.set(id, { data: response.data, time: Number(new Date()) })
+                  }
+                } catch (e) {
             console.error(`Exception during cache processing with id ${id}`, e) // eslint-disable-line
-              }
-            })
-          }
-          if (proxyConfig.onProxyRes) {
-            proxyConfig.onProxyRes(proxyRes, req, res)
+                }
+              })
+            }
+            if (proxyConfig.onProxyRes) {
+              proxyConfig.onProxyRes(proxyRes, req, res)
+            }
           }
-        }
-      }))
-    }
+        }))
+      }
diff --git a/src/utils.js b/src/utils.js
@@ -50,15 +50,21 @@ export interface Cache<K, V> {
     set(key: K, value: V): Cache<K, V>;
 }
 
+export type CacheKeyModifier = (?string, ?Object) => ?string
+
 export const didTimeout = (timeout: number, time: number) =>
   timeout > 0 && ((time + (Number(timeout) * 1000)) < Number(new Date()))
 
-export const calculateArguments = (query: DocumentNode, variables: ?Object) => {
+export const calculateArguments = (query: DocumentNode, variables: ?Object, cacheKeyModifier: ?CacheKeyModifier) => {
   const { id, timeout, modifier } = getDirectiveArgumentsAsObject(query, DIRECTIVE)
-  const thisId = modifier ? modifier.reduce((next, path) => {
+  let thisId = modifier ? modifier.reduce((next, path) => {
     return `${next}.${_get(variables, path, '')}`
   }, id) : id
 
+  if (cacheKeyModifier) {
+    thisId = cacheKeyModifier(thisId, variables)
+  }
+
   if (!thisId) {
     throw new Error(`@${DIRECTIVE} directive requires a unique id.`)
   }

diff --git a/yarn.lock b/yarn.lock
@@ -2390,10 +2390,10 @@ flat-cache@^1.2.1:
     rimraf "~2.6.2"
     write "^0.2.1"
 
-flow-bin@^0.90.0:
-  version "0.90.0"
-  resolved "https://registry.yarnpkg.com/flow-bin/-/flow-bin-0.90.0.tgz#733b6d29a8c8a22b9a5d273611d9a8402faf3445"
-  integrity sha512-/syDchjhLLL7nELK1ggyWJifGXuMCTz74kvkjR1t9DcmasMrilLl9qAAotsACcNb98etEEJpsCrvP7WL64kadw==
+flow-bin@^0.94.0:
+  version "0.94.0"
+  resolved "https://registry.yarnpkg.com/flow-bin/-/flow-bin-0.94.0.tgz#b5d58fe7559705b73a18229f97edfc3ab6ffffcb"
+  integrity sha512-DYF7r9CJ/AksfmmB4+q+TyLMoeQPRnqtF1Pk7KY3zgfkB/nVuA3nXyzqgsIPIvnMSiFEXQcFK4z+iPxSLckZhQ==
 
 flow-copy-source@^2.0.2:
   version "2.0.2"
@@ -2682,10 +2682,10 @@ graceful-fs@^4.1.11, graceful-fs@^4.1.15, graceful-fs@^4.1.2, graceful-fs@^4.1.6
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.1.15.tgz#ffb703e1066e8a0eeaa4c8b80ba9253eeefbfb00"
   integrity sha512-6uHUhOPEBgQ24HM+r6b/QwWfZq+yiFcipKFrOFiBEnWdy5sdzYoi+pJeQaPI5qOLRFqWmAXUPQNsielzdLoecA==
 
-graphql@^14.0.2:
-  version "14.0.2"
-  resolved "https://registry.yarnpkg.com/graphql/-/graphql-14.0.2.tgz#7dded337a4c3fd2d075692323384034b357f5650"
-  integrity sha512-gUC4YYsaiSJT1h40krG3J+USGlwhzNTXSb4IOZljn9ag5Tj+RkoXrWp+Kh7WyE3t1NCfab5kzCuxBIvOMERMXw==
+graphql@^14.1.1:
+  version "14.1.1"
+  resolved "https://registry.yarnpkg.com/graphql/-/graphql-14.1.1.tgz#d5d77df4b19ef41538d7215d1e7a28834619fac0"
+  integrity sha512-C5zDzLqvfPAgTtP8AUPIt9keDabrdRAqSWjj2OPRKrKxI9Fb65I36s1uCs1UUBFnSWTdO7hyHi7z1ZbwKMKF6Q==
   dependencies:
     iterall "^1.2.2"