github.com/cockroachdb/tools@v0.0.0-20230222021103-a6d27438930d/go/analysis/internal/checker/start_test.go (about)

     1  // Copyright 2022 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package checker_test
     6  
     7  import (
     8  	"go/ast"
     9  	"io/ioutil"
    10  	"path/filepath"
    11  	"testing"
    12  
    13  	"golang.org/x/tools/go/analysis"
    14  	"golang.org/x/tools/go/analysis/analysistest"
    15  	"golang.org/x/tools/go/analysis/internal/checker"
    16  	"golang.org/x/tools/go/analysis/passes/inspect"
    17  	"golang.org/x/tools/go/ast/inspector"
    18  	"golang.org/x/tools/internal/testenv"
    19  )
    20  
    21  // TestStartFixes make sure modifying the first character
    22  // of the file takes effect.
    23  func TestStartFixes(t *testing.T) {
    24  	testenv.NeedsGoPackages(t)
    25  
    26  	files := map[string]string{
    27  		"comment/doc.go": `/* Package comment */
    28  package comment
    29  `}
    30  
    31  	want := `// Package comment
    32  package comment
    33  `
    34  
    35  	testdata, cleanup, err := analysistest.WriteFiles(files)
    36  	if err != nil {
    37  		t.Fatal(err)
    38  	}
    39  	path := filepath.Join(testdata, "src/comment/doc.go")
    40  	checker.Fix = true
    41  	checker.Run([]string{"file=" + path}, []*analysis.Analyzer{commentAnalyzer})
    42  
    43  	contents, err := ioutil.ReadFile(path)
    44  	if err != nil {
    45  		t.Fatal(err)
    46  	}
    47  
    48  	got := string(contents)
    49  	if got != want {
    50  		t.Errorf("contents of rewritten file\ngot: %s\nwant: %s", got, want)
    51  	}
    52  
    53  	defer cleanup()
    54  }
    55  
    56  var commentAnalyzer = &analysis.Analyzer{
    57  	Name:     "comment",
    58  	Requires: []*analysis.Analyzer{inspect.Analyzer},
    59  	Run:      commentRun,
    60  }
    61  
    62  func commentRun(pass *analysis.Pass) (interface{}, error) {
    63  	const (
    64  		from = "/* Package comment */"
    65  		to   = "// Package comment"
    66  	)
    67  	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
    68  	inspect.Preorder(nil, func(n ast.Node) {
    69  		if n, ok := n.(*ast.Comment); ok && n.Text == from {
    70  			pass.Report(analysis.Diagnostic{
    71  				Pos: n.Pos(),
    72  				End: n.End(),
    73  				SuggestedFixes: []analysis.SuggestedFix{{
    74  					TextEdits: []analysis.TextEdit{{
    75  						Pos:     n.Pos(),
    76  						End:     n.End(),
    77  						NewText: []byte(to),
    78  					}},
    79  				}},
    80  			})
    81  		}
    82  	})
    83  
    84  	return nil, nil
    85  }