gpython: add a simple test for gpython command

Signed-off-by: Sebastien Binet <[email protected]>

Author: sbinet

main.go

@@ -41,10 +41,12 @@ Full options:
 func main() {
 	flag.Usage = syntaxError
 	flag.Parse()
-	args := flag.Args()
+	xmain(flag.Args())
+}
 
+func xmain(args []string) {
 	opts := py.DefaultContextOpts()
-	opts.SysArgs = flag.Args()
+	opts.SysArgs = args
 	ctx := py.NewContext(opts)
 
 	if *cpuprofile != "" {
@@ -77,5 +79,4 @@ func main() {
 			log.Fatal(err)
 		}
 	}
-
 }

main_test.go

@@ -0,0 +1,61 @@
+// Copyright 2022 The go-python Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"bytes"
+	"flag"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"testing"
+)
+
+var regen = flag.Bool("regen", false, "regenerate golden files")
+
+func TestGPython(t *testing.T) {
+
+	tmp, err := os.MkdirTemp("", "go-python-")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmp)
+
+	exe := filepath.Join(tmp, "out.exe")
+	cmd := exec.Command("go", "build", "-o", exe, ".")
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	err = cmd.Run()
+	if err != nil {
+		t.Fatalf("failed to compile embedding example: %+v", err)
+	}
+
+	got, err := exec.Command(exe, "testdata/hello.py").CombinedOutput()
+	if err != nil {
+		t.Fatalf("could not run gpython:\n%s\nerr: %+v", got, err)
+	}
+
+	const fname = "testdata/hello_golden.txt"
+
+	flag.Parse()
+	if *regen {
+		err = os.WriteFile(fname, got, 0644)
+		if err != nil {
+			t.Fatalf("could not write golden file: %+v", err)
+		}
+	}
+
+	want, err := os.ReadFile(fname)
+	if err != nil {
+		t.Fatalf("could not read golden file: %+v", err)
+	}
+	if !bytes.Equal(got, want) {
+		t.Fatalf("stdout differ:\ngot:\n%s\nwant:\n%s\n", got, want)
+	}
+}
+
+func TestRunFile(t *testing.T) {
+	xmain([]string{"./testdata/hello.py"})
+}

testdata/hello.py

@@ -0,0 +1 @@
+print("hello, world!")

testdata/hello_golden.txt

@@ -0,0 +1 @@
+hello, world!