go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/lucicfg/examples_test.go (about)

     1  // Copyright 2019 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  //go:generate go test . -run TestExamples -test.regen
    16  package lucicfg
    17  
    18  import (
    19  	"context"
    20  	"flag"
    21  	"fmt"
    22  	"os"
    23  	"path/filepath"
    24  	"testing"
    25  
    26  	"go.chromium.org/luci/starlark/interpreter"
    27  )
    28  
    29  var regen = flag.Bool("test.regen", false, "regenerated configs")
    30  
    31  func TestExamples(t *testing.T) {
    32  	t.Parallel()
    33  	fi, err := os.ReadDir("examples")
    34  	if err != nil {
    35  		t.Fatalf("os.ReadDir: %s", err)
    36  	}
    37  	for _, f := range fi {
    38  		if f.IsDir() {
    39  			mainStar := filepath.Join("examples", f.Name(), "main.star")
    40  			t.Run(f.Name(), func(t *testing.T) {
    41  				t.Parallel()
    42  				if err := runExample(mainStar); err != nil {
    43  					t.Fatalf("%s", err)
    44  				}
    45  			})
    46  		}
    47  	}
    48  }
    49  
    50  func runExample(script string) error {
    51  	abs, err := filepath.Abs(script)
    52  	if err != nil {
    53  		return err
    54  	}
    55  
    56  	root, main := filepath.Split(abs)
    57  	output := filepath.Join(root, "generated")
    58  
    59  	state, err := Generate(context.Background(), Inputs{
    60  		Code:        interpreter.FileSystemLoader(root),
    61  		Entry:       main,
    62  		Meta:        &Meta{ConfigDir: "generated"},
    63  		testVersion: "1.1.1",
    64  	})
    65  	if err != nil {
    66  		return err
    67  	}
    68  
    69  	if *regen {
    70  		_, _, err := state.Output.Write(output, true)
    71  		return err
    72  	}
    73  
    74  	// We want examples in examples/... to be formatted using current "golden"
    75  	// style, so do byte-to-byte comparison (not a semantic one).
    76  	cmp, err := state.Output.Compare(output, false)
    77  	if err != nil {
    78  		return err
    79  	}
    80  	var diff []string
    81  	for name, res := range cmp {
    82  		if res == Different {
    83  			diff = append(diff, name)
    84  		}
    85  	}
    86  	if len(diff) != 0 {
    87  		return fmt.Errorf("the following generated files are stale, run `go generate .`: %q", diff)
    88  	}
    89  	return nil
    90  }