codegen_test.go

/*
Copyright 2024 Olivier Mengué

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package codegen_test

import (
	"log"
	"os"
	"strings"
	"testing"

	"github.com/dolmen-go/codegen"
)

func TestExample(t *testing.T) {
	os.Args = make([]string, 2)
	os.Args[1] = "foo"
	const filename = "main_foo.go"

	defer func() {
		f, err := os.Open(filename)
		if err != nil {
			t.Errorf("file " + filename + " not created!")
			t.Fail()
		}
		_ = f.Close()
		if err = os.Remove("main_foo.go"); err == nil {
			log.Printf("File %s removed.\n", filename)
		}
	}()

	Example()
}

// TestParseFailures to reach full coverage.
func TestParseFailures(t *testing.T) {
	_, err := codegen.Parse("{{")
	if err == nil {
		t.Fatal("Parse should fail.")
	}

	err = func() (r error) {
		defer func() {
			r = recover().(error)
		}()
		codegen.MustParse("{{")
		return
	}()
	if err == nil {
		t.Fatal("MustParse should panic.")
	}
}

func TestCreateFileFailures(t *testing.T) {
	const filename = "tmp_test.go"
	// Remove the file just in case.
	// In the normal case (test success), the file is not created because of earlier failures.
	defer os.Remove(filename)

	err := codegen.CreateFile(filename, codegen.MustParse("package codegen_test\n").Template, 0)
	if err == nil || !strings.Contains(err.Error(), "https://golang.org/s/generatedcode") {
		t.Fatal("Error expected")
	}

	err = codegen.MustParse("// Code generated ! DO NOT EDIT.\n\npackage codegen_test\n\n// {{ len 1 }}\n").CreateFile(filename, nil)
	if err == nil || !strings.Contains(err.Error(), "len") {
		t.Log("Error:", err)
		t.Fatal("Error expected when evaluating the template (because of epression `len 1`)")
	}

}