add base files

Author: cvburgess

.eslintrc

@@ -0,0 +1,15 @@
+{
+  "plugins": ["node", "prettier"],
+  "parserOptions": {
+    "ecmaVersion": 2018
+  },
+  "env": {
+    "jest": true,
+    "node": true
+  },
+  "extends": ["eslint:recommended", "plugin:node/recommended", "plugin:prettier/recommended"],
+  "rules": {
+    "node/exports-style": ["error", "module.exports"],
+    "prettier/prettier": "error"
+  }
+}

.npmignore

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+*.test.js

README.md

@@ -1 +1,61 @@
 # SQLDataSource
+
+This package combines the power of Knex with the ease of use of Apollo DataSources.
+
+## Getting Started
+
+### Installation
+
+`npm i datasource-sql`
+
+### Usage
+
+```js
+const Knex = require("knex");
+const { SQLDataSource } = require("datasource-sql");
+
+const MINUTE = 60 * 1000;
+
+const knex = Knex({
+  client: "pg",
+  connection: {
+    /* CONNECTION INFO */
+  }
+});
+
+class MyDatabase extends SQLDataSource {
+  constructor() {
+    super();
+    // Add your instance of Knex to the DataSource
+    this.knex = knex;
+  }
+
+  getUsers() {
+    // This can be any valid Knex query
+    const query = this.db.select().from("users");
+
+    // Batch the query and cache the result for 1 minute
+    return this.getBatchedAndCached(query, MINUTE);
+  }
+}
+```
+
+And use it in your Apollo server configuration:
+
+```js
+const server = new ApolloServer({
+  typeDefs,
+  resolvers,
+  cache,
+  context,
+  dataSources: () => ({
+    db: new MyDatabase()
+  })
+});
+```
+
+## Contributing
+
+All contributions are welcome!
+
+Please open an issue or pull request.

SQLCache.js

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+const { InMemoryLRUCache } = require("apollo-server-caching");
+const DataLoader = require("dataloader");
+
+class SQLCache {
+  constructor(cache = new InMemoryLRUCache(), knex) {
+    this.cache = cache;
+    this.loader = new DataLoader(rawQueries =>
+      Promise.all(rawQueries.map(rawQuery => knex.raw(rawQuery)))
+    );
+  }
+
+  getBatched(query) {
+    const queryString = query.toString();
+    return this.loader.load(queryString).then(result => result && result.rows);
+  }
+
+  getCached(query, ttl) {
+    const queryString = query.toString();
+    const cacheKey = `sqlcache:${queryString}`;
+
+    return this.cache.get(cacheKey).then(entry => {
+      if (entry) return Promise.resolve(entry);
+      return query.then(rows => {
+        if (rows) this.cache.set(cacheKey, rows, ttl);
+        return Promise.resolve(rows);
+      });
+    });
+  }
+
+  getBatchedAndCached(query, ttl) {
+    const queryString = query.toString();
+    const cacheKey = `sqlcache:${queryString}`;
+
+    return this.cache.get(cacheKey).then(entry => {
+      if (entry) return Promise.resolve(entry);
+      return this.loader
+        .load(queryString)
+        .then(result => result && result.rows)
+        .then(rows => {
+          if (rows) this.cache.set(cacheKey, rows, ttl);
+          return Promise.resolve(rows);
+        });
+    });
+  }
+}
+
+module.exports = SQLCache;

SQLDataSource.js

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+const SQLCache = require("./SQLCache");
+const knexTinyLogger = require("knex-tiny-logger").default;
+
+const { DEBUG } = process.env;
+
+class SQLDataSource {
+  initialize(config) {
+    if (DEBUG) knexTinyLogger(this.knex); // Add a logging utility for debugging
+    this.context = config.context;
+    this.db = this.knex;
+    this.sqlCache = new SQLCache(config.cache, this.knex);
+    this.getBatched = query => this.sqlCache.getBatched(query);
+    this.getCached = (query, ttl) => this.sqlCache.getCached(query, ttl);
+    this.getBatchedAndCached = (query, ttl) =>
+      this.sqlCache.getBatchedAndCached(query, ttl);
+  }
+}
+
+module.exports = SQLDataSource;

index.js

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+const SQLCache = require("./SQLCache");
+const SQLDataSource = require("./SQLDataSource");
+
+module.exports = { SQLCache, SQLDataSource };