Go Testing and Scripting Pattern

Originally it's Mockery-example

Example case for mockery issue #128 filed with the golang tool "mockery".

But right now, I added more complex examples

Topics

• Mock

Scripts

• Remove duplicated vscode plugin on mac

Mock notes:

How to generate S3API from vendor code ?

use go mod vendor to download code

warning

• s3 is a struct, so

mockgen --build_flags=--mod=mod github.com/aws/aws-sdk-go/service/s3 S3 is wrong

1. Mockgen

S3API is interface

mockgen --build_flags=--mod=mod github.com/aws/aws-sdk-go/service/s3/s3iface S3API > mocks/second_mocks.go

2. Mockery

What if I want mockery api for mocking and generation ??

1. add _ "github.com/aws/aws-sdk-go/service/s3/s3iface/interface.go"
2. go mod vendor
3. run below, but mocks/S3API.go will be overwritten !!!

mockery --dir vendor/github.com/aws/aws-sdk-go/service/s3/s3iface --name S3API

other takeaway cmds

run go mod vendor to pull code

mockgen --build_flags=--mod=mod vendor/github.com/aws/aws-sdk-go/service/s3 S3

import _ "github.com/golang/mock/mockgen/model"

Issue of method 2 under Q&A readme of mockgen

Better try method 3 !

mockgen vendor/github.com/aws/aws-sdk-go/service/s3 S3

prog.go:14:2: use of vendored package not allowed
prog.go:12:2: no required module provides package github.com/golang/mock/mockgen/model: go.mod file not found in current directory or any parent directory; see 'go help modules'
prog.go:14:2: vendor/github.com/aws/aws-sdk-go/service/s3 must be imported as github.com/aws/aws-sdk-go/service/s3
2022/01/21 17:54:17 Loading input failed: exit status 1

Buggy Test Coverage

run test with coverage. shows main.go 0% covered, but mocks folder has 33%!!!

Why on earth we calculate coverage stats on that bits !!

Futures

1. Why gomock or mockery not generate from struct as extra feature, as in case of s3 struct.

2. gcp sdk Has more good pratices

3. more gcp shows fake data has been set in google style.

But, this blog points out:

Google engineer prefer hand-code fake rather reflection mock

Andrew Gerrand mentions gomock, a mocking library, and reluctantly says

[mocking libraries like gomock] are fine, 
but I find that on balance the hand-written fakes tend be easier to reason about 
and clearer to see what's going on, but I'm not an enterprise go programmer 
so maybe people do need that so I don't know, but that's my advice.

4. uber/kraken Manually create s3 interface. But their Makefile mockgen heaps of stuff !!

5. aws-go Lots of http code

6. counterfeiter demo by mario Probably interesting