feat: add KV store

package.json

@@ -52,14 +52,16 @@
     "test": "test"
   },
   "dependencies": {
-    "is-promise": "^4.0.0"
+    "is-promise": "^4.0.0",
+    "node-fetch": "^2.6.1"
   },
   "devDependencies": {
     "@commitlint/cli": "^12.0.0",
     "@commitlint/config-conventional": "^12.0.0",
     "@netlify/eslint-config-node": "^3.1.4",
     "ava": "^2.4.0",
     "husky": "^4.3.8",
+    "nock": "^13.1.0",
     "nyc": "^15.0.0"
   },
   "engines": {

src/lib/consts.js

@@ -2,10 +2,12 @@ const BUILDER_FUNCTIONS_FLAG = true
 const HTTP_STATUS_METHOD_NOT_ALLOWED = 405
 const HTTP_STATUS_OK = 200
 const METADATA_VERSION = 1
+const STORE_ENDPOINT = 'https://functions-kv.netlify.app'
 
 module.exports = {
   BUILDER_FUNCTIONS_FLAG,
   HTTP_STATUS_METHOD_NOT_ALLOWED,
   HTTP_STATUS_OK,
   METADATA_VERSION,
+  STORE_ENDPOINT,
 }

src/lib/store.d.ts

@@ -0,0 +1,17 @@
+export interface ObjectDescription {
+  lastModified: string
+  key: string
+}
+export interface ListResponse<T = any> {
+  count: number
+  objects: Array<ObjectDescription>
+}
+export interface Store {
+  get<T = any>(key: string): Promise<T>
+  set<T = any>(key: string, value: T): Promise<boolean>
+  delete(key: string): Promise<boolean>
+  list(prefix: string): Promise<ListResponse>
+  patch<T extends Record<string, any>>(key: string, value: Partial<T>): Promise<T>
+}
+
+export function getStore(context: HandlerContext): Store

src/lib/store.js

@@ -0,0 +1,95 @@
+// @ts-check
+
+const process = require('process')
+
+const { default: fetch } = require('node-fetch')
+
+const { STORE_ENDPOINT } = require('./consts')
+
+const isValidKey = (key) => key && typeof key === 'string'
+
+/**
+ * A key-value store object. Expects a context with `context.clientContext.store.token`
+ *
+ * @param {import("../..").HandlerContext} context
+ * @returns Promise<Store>
+ */
+module.exports.getStore = function getStore(context) {
+  const headers = { authorization: `Bearer ${context.clientContext.blobstore.token}` }
+  const endpoint = process.env.STORE_ENDPOINT || STORE_ENDPOINT
+  return {
+    async get(key) {
+      if (!isValidKey(key)) {
+        throw new Error('Invalid key')
+      }
+      const response = await fetch(`${endpoint}/item/${encodeURIComponent(key)}`, { headers })
+      if (response.status === 404) {
+        return
+      }
+      if (!response.ok) {
+        throw new Error(`There was an error loading the value for key ${key}: ${response.statusText}`)
+      }
+      try {
+        return response.json()
+      } catch (error) {
+        throw new Error(`Error parsing value for key ${key}`)
+      }
+    },
+    async set(key, value) {
+      if (!isValidKey(key)) {
+        throw new Error('Invalid key')
+      }
+
+      let body
+      try {
+        body = JSON.stringify(value)
+      } catch (error) {
+        throw new Error(`Could not serialize value for key ${key}. Item must be JSON-serializable`)
+      }
+      const response = await fetch(`${endpoint}/item/${encodeURIComponent(key)}`, {
+        method: 'PUT',
+        headers,
+        body,
+      })
+      if (!response.ok) {
+        throw new Error(`There was an error setting key ${key}: ${response.statusText}`)
+      }
+      return true
+    },
+
+    async delete(key) {
+      if (!isValidKey(key)) {
+        throw new Error('Invalid key')
+      }
+
+      const response = await fetch(`${endpoint}/item/${encodeURIComponent(key)}`, { method: 'DELETE', headers })
+
+      if (response.status === 404) {
+        return false
+      }
+
+      if (!response.ok) {
+        throw new Error(`There was an error setting key ${key}: ${response.statusText}`)
+      }
+      return true
+    },
+
+    async list(prefix) {
+      if (!isValidKey(prefix)) {
+        throw new Error('Invalid key')
+      }
+      const response = await fetch(`${endpoint}/list/${encodeURIComponent(prefix)}`, { headers })
+      if (response.status === 404) {
+        return { count: 0, objects: [] }
+      }
+      if (!response.ok) {
+        throw new Error(`There was an error loading the value for prefix ${prefix}: ${response.statusText}`)
+      }
+      try {
+        return response.json()
+      } catch (error) {
+        throw new Error(`Error parsing value for key ${prefix}`)
+      }
+    },
+  }
+}

src/main.d.ts

@@ -1,2 +1,3 @@
 export * from './lib/builder'
+export * from './lib/store'
 export * from './function'

src/main.js

@@ -1,3 +1,4 @@
 const { builder } = require('./lib/builder')
+const { getStore } = require('./lib/store')
 
-module.exports = { builder }
+module.exports = { builder, getStore }