em-shea

import os
import boto3

# Explicitly specifying where the default AWS region is found 
# (as an environment variable) to be able to mock it in the test
s3_client = boto3.client('s3', region_name=os.environ['AWS_REGION'])
translate_client = boto3.client('translate', region_name=os.environ['AWS_REGION'])

def lambda_handler(event, context):
    print(event)

em-shea

    # Mock S3 new file uploaded event
    def s3_upload_event(self, file_name):

        return {
            "Records":[
            {
                "eventVersion":"2.1",
                "eventSource":"aws:s3",
                "awsRegion":"us-east-1",
                "eventTime":"2021-06-18T16:03:17.567Z",

em-shea

class TranslateFileTest(unittest.TestCase):

    # Test for valid file type (.txt)
    @mock.patch('translate_file.app.read_file', side_effect=mocked_read_file)
    @mock.patch('translate_file.app.translate_text', side_effect=mocked_translate_text)
    def test_valid_file(self, translate_text_mock, read_file_mock):

        response = lambda_handler(self.s3_upload_event("valid_file.txt"), "")
        expected_response = {
            "success": True,

em-shea

# Mock call to S3 to read file
def mocked_read_file(bucket_name, key_name):
    return "我爱写单元测试！"

# Mock call to Translate to translate file text
def mocked_translate_text(original_text):
    return {
       "original_text":"我爱写单元测试！",
       "translated_text":"I love writing unit tests!",
       "original_language":"zh",

em-shea

# Appending the src/ directory to the path
# in order to run tests on function code in a different directory
import sys
sys.path.append('../../')

import unittest
from unittest import mock

# Setting the default AWS region environment variable required by the Python SDK boto3
with mock.patch.dict('os.environ', {'AWS_REGION': 'us-east-1'}):

em-shea

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "iam:*",
                "lambda:*",
                "cloudformation:*",
                "sns:CreateTopic",

em-shea

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Description: An example SAM template for a Lambda function that's invoked by a CloudWatch Event.

Resources:
  MyFunction:
    Type: 'AWS::Serverless::Function'
    Properties:
      FunctionName: MyFunction
      Handler: MyFunction.lambda_handler

em-shea

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Description: An example SAM template for a Lambda function invoked by API Gateway.

Resources:
  MyFunction:
    Type: 'AWS::Serverless::Function'
    Properties:
      FunctionName: MyFunction
      Handler: MyFunction.lambda_handler

em-shea

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Description: An example SAM template for a Lambda & API Gateway app that sends messages using SNS.
Parameters:
  # For any variables you don't want stored in your repo, you can pass them through the SAM deploy command
  # Ie, sam deploy .... --parameter-overrides MyEmail=myemail@gmail.com
  MyEmail:
    Type: String

Resources:

em-shea

AWSTemplateFormatVersion: '2010-09-09'
Transform: 'AWS::Serverless-2016-10-31'
Description: An app that includes a DynamoDB table, Lambda function that writes to DynamoDB, and CloudWatch Event trigger

Resources:
  LambdaWriteToDynamoDB:
    # A function that writes to a DynamoDB table on a schedule
    Type: 'AWS::Serverless::Function'
    Properties:
      FunctionName: LambdaWriteToDynamoDB