If I give a flag (in golang) as 'test*.txt' (as a CLI argument), I need to open all files of the said format (example: test.txt, test1.txt, test2.txt).
I am thinking of doing a regex match with all the files present in the folder. Is there a better way?
You can use the filepath.Glob function:
package main
import (
"fmt"
"path/filepath"
)
func main() {
matches, _ := filepath.Glob("test*.txt")
for _, p := range matches {
fmt.Println(p)
}
}
I've the following function and I need to create a unit test for it
package main
import (
"fmt"
"io/ioutil"
"os"
)
type Source struct {
Path string
}
type fileReader interface {
readOneFile() ([]byte, error)
}
func(s Source) readOneFile() ([]byte, error) {
cwd, err := os.Getwd()
file, err := ioutil.ReadFile(fmt.Sprintf("%s/file.txt", cwd))
if err != nil {
return nil, fmt.Errorf("erro reading file : %s", err.Error())
}
return file, err
}
The problem is that I use path to file in the method, what it the best practice in go to create a unit test for this kind of functions ?
Tests will run in the directory that contains the tests
So Getwd will give the path to that directory
The filename for test data in files in test directories should begin with underscore _
However, your program needs a file called "file.txt" . To support testing this filepath that does not start with _ create the file file.txt in (for example) /tmp, do a chdir to /tmp immediately before running the test and let the test pick up the file that was just made
For writing unit test you need to create a file within same package with fileName_test.go
Suppose your file name read.go so your test file name should be read_test.go.
read_test.go
package main
import (
"testing"
"fmt"
)
func TestReadOneFile(t *testing.T) {
var a Source
f, err := a.readOneFile()
if err != nil {
t.Errorf("incorrect")
} else {
fmt.Println("passed")
}
}
Here you have to named your test function name with Test as prefix and need to import package testing.
After creating the unit test you can check the code coverage by running below two commands:
1. go test --coverprofile coverage.out
2. go tool cover -html=coverage.out
I am fairly new to golang and am finding myself frustrated with a simple file service program. I am suspecting that there is something wrong with my file prefix/ directory in the handler for my router r. I have tried many different formats for the directory. the html file i would like serviced is $HOME/Documents/TEST/Login on my system. Below is my code, note the {address} replaces the ip address.
package main
import (
"log"
"github.com/gorilla/mux"
"net/http"
"time"
)
func main() {
r := mux.NewRouter()
r.PathPrefix("/Login/").Handler(http.StripPrefix("/Login/",
http.FileServer(http.Dir("$HOME/Documents/TEST/Login"))))
srv := &http.Server{
Handler: r,
Addr: "{address}:9999",
WriteTimeout: 600 * time.Second,
ReadTimeout: 600 * time.Second,
}
log.Fatal(srv.ListenAndServe())
}
Go won't interpret $HOME. Use an explicit path such as /home/username/Documents/TEST/Login/.
I'm writing some unit tests for my application in Go. The tests fail however because it cannot find the configuration files. Normally the binary looks for the configuration files in the working directory under the path conf/*.conf.
I figured that browsing to the directory that has conf/ and running go test in it would solve it, but it still reports that the file system cannot find the path specified.
How can I tell go test to use a certain directory as the working directory so that the tests may actually be executed?
You may be able to use the Caller to get the path to the current test source file, like this:
package sample
import (
"testing"
"runtime"
"fmt"
)
func TestGetFilename(t *testing.T) {
_, filename, _, _ := runtime.Caller(0)
t.Logf("Current test filename: %s", filename)
}
I do not believe this is possible. I have not been able to find documentation stating this explicitly, but I believe go test always uses the package directory (containing the go source files) as the working directory.
As a workaround, I compiled the test and execute the test from the current directory.
go test -c && ./<mypackage>.test
Or, if you want a generic command that you can use, you can rename the test file with -o option.
go test -c -o xyz.test && ./xyz.test
While not really convenient, you can always pass it as a command line variable, for example :
package blah_test
import (
"flag"
"fmt"
"os"
"testing"
)
var (
cwd_arg = flag.String("cwd", "", "set cwd")
)
func init() {
flag.Parse()
if *cwd_arg != "" {
if err := os.Chdir(*cwd_arg); err != nil {
fmt.Println("Chdir error:", err)
}
}
}
func TestBlah(t *testing.T) {
t.Errorf("cwd: %+q", *cwd_arg)
}
Then run it like :
┌─ oneofone#Oa [/tmp]
└──➜ go test . -cwd="$PWD"
--- FAIL: TestBlah (0.00 seconds)
blah_test.go:16: cwd: "/tmp"
No matter where the work directory is. It must be under your project Dir. So my solution is
wd, _ := os.Getwd()
for !strings.HasSuffix(wd, "<yourProjectDirName>") {
wd = filepath.Dir(wd)
}
raw, err := ioutil.ReadFile(fmt.Sprintf("%s/src/conf/conf.dev.json", wd))
Your path should always start from your project Dir. Every time you read the file in a package and accessed by main.go or your another package unit test. It will always work.
You can use the os package.
You would want to do something like this
func TestMyFunction(t *testing.T) {
os.Chdir("./path")
//TEST FUNCTION
os.Chdir("..")
}
There are several possibilities in the os package.
To add init function into *_test.go under your test package.
Test package will run this function before test function start.
func init() {
_, filename, _, _ := runtime.Caller(0)
// The ".." may change depending on you folder structure
dir := path.Join(path.Dir(filename), "..")
err := os.Chdir(dir)
if err != nil {
panic(err)
}
}
I know this is an old question but I had the same problem trying to use migrations for the database on my tests, and maybe this solution helps someone.
Since there is no native way of getting the project directory, you could identify some file or directory that you know it's only in the root of the project (in my case, it was the relative directory database/migrations). Once you have this unique relative directory, you could have a function like the following to obtain the project root directory. It just gets the current working directory (assuming it's inside the project's directory) and starts to navigate all the way up until it finds a dir that has the relative directory you know it's on the root of the project:
func FindMyRootDir() string {
workingDirectory, err := os.Getwd()
if err != nil {
panic(err)
}
lastDir := workingDirectory
myUniqueRelativePath := "database/migrations"
for {
currentPath := fmt.Sprintf("%s/%s", lastDir, myUniqueRelativePath)
fi, err := os.Stat(currentPath)
if err == nil {
switch mode := fi.Mode(); {
case mode.IsDir():
return currentPath
}
}
newDir := filepath.Dir(lastDir)
// Ooops, we couldn't find the root dir. Check that your "myUniqueRelativePath" really exists
if newDir == "/" || newDir == lastDir {
return ""
}
lastDir = newDir
}
}
Of course it's not the most beautiful solution, but it works.
I've had a similar problem and found the solution on this blog
Basically you can change the folder that the test is running using a similar function:
package main
import (
"os"
"path"
"runtime"
)
func MakeFunctionRunOnRootFolder() {
_, filename, _, _ := runtime.Caller(0)
// The ".." may change depending on you folder structure
dir := path.Join(path.Dir(filename), "..")
err := os.Chdir(dir)
if err != nil {
panic(err)
}
}
Go 1.20 is getting new -C arguments for "go subcommands" so this should help:
go test -C directory/ ...
It's a common practice in Go to place test fixtures in same package inside testdata folder.
Some examples from standard library:
debug/elf
net/http
image
Also, there is a post from Dave Cheney, where he suggests following code:
f, err := os.Open("testdata/somefixture.json")
I currently use a neat solution for this problem, instead of opening the file directly by calling os.Open(), I use the embed package in a smart way:
First I create a global variable in my root package called:
//go:embed config/* otherdirectories/*
var RootFS embed.FS
Then I just open the files inside my tests by using this global variable, e.g.:
func TestOpenConfig(t *testing.T) {
configFile, err := rootpkg.RootFS.ReadFile("config/env")
if err != nil {
t.Fatalf("unable to open config/env file: %s", err)
}
if string(configFile) != "FOO=bar\n" {
t.Fatalf("config file contents differ from expected: %s", string(configFile))
}
}
This is a neat trick because now you can always work with relative paths from your root package, which is what I used to do in other programming languages.
Of course, this has the restriction that you will need to import your root package, which depending on your package layout might not be ideal because of cyclic imports. If this is your case you might just create a embed.go file inside the config directory itself and call
your configs by name.
One other drawback is that you are embedding test files in your binary, this is probably ok if your test files are not very big, like megabytes big, so I don't really mind this issue.
I also created a repository for illustrating this solution:
https://github.com/VinGarcia/golang-reading-files-from-tests
I would use an Environment Variable for the location of your application. It seems to be the best way when running go tools, as test programs can be run from a temporary location.
// get home dir of app, use MYAPPHOME env var if present, else executable dir.
func exeDir() string {
dir, exists := os.LookupEnv("MYAPPHOME")
if exists {
return dir
} else {
ex, err := os.Executable()
if err != nil {
panic(err)
}
exPath := path.Dir(ex)
return exPath
}
}
My implementation of AWS Request Authentication in Google Go lang
package main
import "fmt"
import "crypto/hmac"
import "crypto/sha256"
import "time"
import "encoding/base64"
func main() {
AWSAccessKeyId := "MHAPUBLICKEY"
AWSSecretKeyId := "MHAPRIVATEKEY"
sha256 := sha256.New
time := time.Now().UTC().Format(time.ANSIC)
hash := hmac.New(sha256, []byte(AWSSecretKeyId))
hash.Write([]byte(time))
sha := base64.URLEncoding.EncodeToString(hash.Sum(nil))
fmt.Println("Date", time)
fmt.Println("Content-Type","text/xml; charset=UTF-8")
fmt.Println("AWS3-HTTPS AWSAccessKeyId=" + AWSAccessKeyId + ",Algorithm=HmacSHA256,Signature=" + sha)
}
I get valid output from Amazon but only when the 'sha' hash does not contain any _ or -
Working
'WFKzWNQlZEyTC9JFGFyqdf8AYj54aBj5btxPIaGTDbM='
Not Working HTTP/1.1 403 Forbidden SignatureDoesNotMatch
'h-FIs7of_CJ7LusAoQPzSWVt9hlXF_5gCQgedn_85lk='
How do I encode the AWS3-HTTPS header so it works in either circumstance? Just incase it's relevant, I am currently copy and pasting the output into cURL. I plan on implementing the request in Google Go once I have it working reliably.
I turned out I needed to change from URLEncoding to StdEncoding
sha = base64.URLEncoding.EncodeToString(hash.Sum(nil))
to
sha = base64.StdEncoding.EncodeToString(hash.Sum(nil))