Merge branch 'new-master'

Author: fwang

billing.js

@@ -1,24 +1,20 @@
 import stripePackage from "stripe";
+import handler from "./libs/handler-lib";
 import { calculateCost } from "./libs/billing-lib";
-import { success, failure } from "./libs/response-lib";
 
-export async function main(event, context) {
+export const main = handler(async (event, context) => {
   const { storage, source } = JSON.parse(event.body);
   const amount = calculateCost(storage);
   const description = "Scratch charge";
 
   // Load our secret key from the  environment variables
   const stripe = stripePackage(process.env.stripeSecretKey);
 
-  try {
-    await stripe.charges.create({
-      source,
-      amount,
-      description,
-      currency: "usd"
-    });
-    return success({ status: true });
-  } catch (e) {
-    return failure({ message: e.message });
-  }
-}
+  await stripe.charges.create({
+    source,
+    amount,
+    description,
+    currency: "usd"
+  });
+  return { status: true };
+});

create.js

@@ -1,11 +1,19 @@
-import uuid from "uuid";
-import * as dynamoDbLib from "./libs/dynamodb-lib";
-import { success, failure } from "./libs/response-lib";
+import * as uuid from "uuid";
+import handler from "./libs/handler-lib";
+import dynamoDb from "./libs/dynamodb-lib";
 
-export async function main(event, context) {
+export const main = handler(async (event, context) => {
   const data = JSON.parse(event.body);
   const params = {
     TableName: process.env.tableName,
+    // 'Item' contains the attributes of the item to be created
+    // - 'userId': user identities are federated through the
+    //             Cognito Identity Pool, we will use the identity id
+    //             as the user id of the authenticated user
+    // - 'noteId': a unique uuid
+    // - 'content': parsed from request body
+    // - 'attachment': parsed from request body
+    // - 'createdAt': current Unix timestamp
     Item: {
       userId: event.requestContext.identity.cognitoIdentityId,
       noteId: uuid.v1(),
@@ -15,10 +23,7 @@ export async function main(event, context) {
     }
   };
 
-  try {
-    await dynamoDbLib.call("put", params);
-    return success(params.Item);
-  } catch (e) {
-    return failure({ status: false });
-  }
-}
+  await dynamoDb.put(params);
+
+  return params.Item;
+});

delete.js

@@ -1,7 +1,7 @@
-import * as dynamoDbLib from "./libs/dynamodb-lib";
-import { success, failure } from "./libs/response-lib";
+import handler from "./libs/handler-lib";
+import dynamoDb from "./libs/dynamodb-lib";
 
-export async function main(event, context) {
+export const main = handler(async (event, context) => {
   const params = {
     TableName: process.env.tableName,
     // 'Key' defines the partition key and sort key of the item to be removed
@@ -13,10 +13,7 @@ export async function main(event, context) {
     }
   };
 
-  try {
-    await dynamoDbLib.call("delete", params);
-    return success({ status: true });
-  } catch (e) {
-    return failure({ status: false });
-  }
-}
+  await dynamoDb.delete(params);
+
+  return { status: true };
+});

get.js

@@ -1,7 +1,7 @@
-import * as dynamoDbLib from "./libs/dynamodb-lib";
-import { success, failure } from "./libs/response-lib";
+import handler from "./libs/handler-lib";
+import dynamoDb from "./libs/dynamodb-lib";
 
-export async function main(event, context) {
+export const main = handler(async (event, context) => {
   const params = {
     TableName: process.env.tableName,
     // 'Key' defines the partition key and sort key of the item to be retrieved
@@ -13,15 +13,11 @@ export async function main(event, context) {
     }
   };
 
-  try {
-    const result = await dynamoDbLib.call("get", params);
-    if (result.Item) {
-      // Return the retrieved item
-      return success(result.Item);
-    } else {
-      return failure({ status: false, error: "Item not found." });
-    }
-  } catch (e) {
-    return failure({ status: false });
+  const result = await dynamoDb.get(params);
+  if ( ! result.Item) {
+    throw new Error("Item not found.");
   }
-}
+
+  // Return the retrieved item
+  return result.Item;
+});

libs/debug-lib.js

@@ -0,0 +1,42 @@
+import AWS from "aws-sdk";
+import util from "util";
+
+// Log AWS SDK calls
+AWS.config.logger = { log: debug };
+
+let logs;
+let timeoutTimer;
+
+export function init(event, context) {
+  logs = [];
+
+  // Log API event
+  debug("API event", {
+    body: event.body,
+    pathParameters: event.pathParameters,
+    queryStringParameters: event.queryStringParameters,
+  });
+
+  // Start timeout timer
+  timeoutTimer = setTimeout(() => {
+    timeoutTimer && flush(new Error("Lambda will timeout in 100 ms"));
+  }, context.getRemainingTimeInMillis() - 100);
+}
+
+export function end() {
+  // Clear timeout timer
+  clearTimeout(timeoutTimer);
+  timeoutTimer = null;
+}
+
+export function flush(e) {
+  logs.forEach(({ date, string }) => console.debug(date, string));
+  console.error(e);
+}
+
+export default function debug() {
+  logs.push({
+    date: new Date(),
+    string: util.format.apply(null, arguments),
+  });
+}

libs/dynamodb-lib.js

@@ -1,7 +1,11 @@
 import AWS from "aws-sdk";
 
-export function call(action, params) {
-  const dynamoDb = new AWS.DynamoDB.DocumentClient();
+const client = new AWS.DynamoDB.DocumentClient();
 
-  return dynamoDb[action](params).promise();
-}
+export default {
+  get   : (params) => client.get(params).promise(),
+  put   : (params) => client.put(params).promise(),
+  query : (params) => client.query(params).promise(),
+  update: (params) => client.update(params).promise(),
+  delete: (params) => client.delete(params).promise(),
+};

libs/handler-lib.js

@@ -0,0 +1,30 @@
+import * as debug from "./debug-lib";
+
+export default function handler(lambda) {
+  return function (event, context) {
+    return Promise.resolve()
+      // Start debugger
+      .then(() => debug.init(event, context))
+      // Run the Lambda
+      .then(() => lambda(event, context))
+      // On success
+      .then((responseBody) => [200, responseBody])
+      // On failure
+      .catch((e) => {
+        // Print debug messages
+        debug.flush(e);
+        return [500, { error: e.message }];
+      })
+      // Return HTTP response
+      .then(([statusCode, body]) => ({
+        statusCode,
+        headers: {
+          "Access-Control-Allow-Origin": "*",
+          "Access-Control-Allow-Credentials": true,
+        },
+        body: JSON.stringify(body),
+      }))
+      // Cleanup debugger
+      .finally(debug.end);
+  };
+}

list.js

@@ -1,7 +1,7 @@
-import * as dynamoDbLib from "./libs/dynamodb-lib";
-import { success, failure } from "./libs/response-lib";
+import handler from "./libs/handler-lib";
+import dynamoDb from "./libs/dynamodb-lib";
 
-export async function main(event, context) {
+export const main = handler(async (event, context) => {
   const params = {
     TableName: process.env.tableName,
     // 'KeyConditionExpression' defines the condition for the query
@@ -16,11 +16,8 @@ export async function main(event, context) {
     }
   };
 
-  try {
-    const result = await dynamoDbLib.call("query", params);
-    // Return the matching list of items in response body
-    return success(result.Items);
-  } catch (e) {
-    return failure({ status: false });
-  }
-}
+  const result = await dynamoDb.query(params);
+
+  // Return the matching list of items in response body
+  return result.Items;
+});

mocks/delete-event.json

@@ -1,6 +1,6 @@
 {
   "pathParameters": {
-    "id": "578eb840-f70f-11e6-9d1a-1359b3b22944"
+    "id": "2b82e2c0-793f-11ea-9602-6d514f529482"
   },
   "requestContext": {
     "identity": {

mocks/get-event.json

@@ -1,6 +1,6 @@
 {
   "pathParameters": {
-    "id": "578eb840-f70f-11e6-9d1a-1359b3b22944"
+    "id": "2b82e2c0-793f-11ea-9602-6d514f529482"
   },
   "requestContext": {
     "identity": {