[mkdir] barebones commands test structure

.gitignore

@@ -1 +1,2 @@
 build*/
+tmp/

Makefile

@@ -23,8 +23,8 @@ build:
 run:
 	go run coreutils/$(UTIL)/$(UTIL).go $(ARGS)
 
-test:
-	go test ./coreutils/...
+test: build
+	PREFIX="$(BIN_PREFIX)" BUILD_DIR="$(shell pwd)/$(BUILD_DIR)" go test ./coreutils/...
 	go test ./internal/...
 
 install:

coreutils/mkdir/mkdir_test.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"os"
+	"testing"
+
+	"codeberg.org/whou/simpleutils/internal/test"
+)
+
+func TestParentsNoErrIfDirExists(t *testing.T) {
+	binPrefix := os.Getenv("PREFIX")
+	if binPrefix == "" {
+		t.Fatal("Required PREFIX environment variable not found.")
+	}
+
+	binDir := os.Getenv("BUILD_DIR")
+	if binDir == "" {
+		t.Fatal("Required BUILD_DIR environment variable not found.")
+	}
+
+	binPath := binDir + "/" + binPrefix + "mkdir"
+
+	// create directory
+	testDir := t.TempDir()
+
+	// try use mkdir in the already created directory with `-p` flag
+	out, code, err := test.GetCmdOutput(binPath, "-p", testDir)
+	t.Log(out)
+
+	if code != 0 {
+		t.Fatalf("Process ran with err \"%v\", expected exit status 0.", err)
+	}
+}

internal/test/util.go

@@ -49,10 +49,17 @@ func GetFuncOutput(function func(), testName string) (string, error) {
 	return string(out), err
 }
 
-// get a command's stdout
-func GetCmdOutput(command string) (string, error) {
-	cmd := exec.Command(command)
+// get a command's stdout and exit code
+func GetCmdOutput(command string, arg ...string) (string, int, error) {
+	cmd := exec.Command(command, arg...)
 	out, err := cmd.CombinedOutput()
 
-	return string(out), err
+	var code int
+	if exitErr, ok := err.(*exec.ExitError); ok {
+		code = exitErr.ExitCode()
+	} else if err != nil {
+		code = -1
+	}
+
+	return string(out), code, err
 }