issues_test.go

Documentation: go/ast

     1  // Copyright 2019 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 ast_test
     6  
     7  import (
     8  	"go/ast"
     9  	"go/parser"
    10  	"go/token"
    11  	"testing"
    12  )
    13  
    14  func TestIssue33649(t *testing.T) {
    15  	for _, src := range []string{
    16  		`package p; func _()`,
    17  		`package p; func _() {`,
    18  		`package p; func _() { _ = 0`,
    19  		`package p; func _() { _ = 0 }`,
    20  	} {
    21  		fset := token.NewFileSet()
    22  		f, _ := parser.ParseFile(fset, "", src, parser.AllErrors)
    23  		if f == nil {
    24  			panic("invalid test setup: parser didn't return an AST")
    25  		}
    26  
    27  		// find corresponding token.File
    28  		var tf *token.File
    29  		fset.Iterate(func(f *token.File) bool {
    30  			tf = f
    31  			return true
    32  		})
    33  		tfEnd := tf.Base() + tf.Size()
    34  
    35  		fd := f.Decls[len(f.Decls)-1].(*ast.FuncDecl)
    36  		fdEnd := int(fd.End())
    37  
    38  		if fdEnd != tfEnd {
    39  			t.Errorf("%q: got fdEnd = %d; want %d (base = %d, size = %d)", src, fdEnd, tfEnd, tf.Base(), tf.Size())
    40  		}
    41  	}
    42  }
    43  
    44  // TestIssue28089 exercises the IsGenerated function.
    45  func TestIssue28089(t *testing.T) {
    46  	for i, test := range []struct {
    47  		src  string
    48  		want bool
    49  	}{
    50  		// No file comments.
    51  		{`package p`, false},
    52  		// Irrelevant file comments.
    53  		{`// Package p doc.
    54  package p`, false},
    55  		// Special comment misplaced after package decl.
    56  		{`// Package p doc.
    57  package p
    58  // Code generated by gen. DO NOT EDIT.
    59  `, false},
    60  		// Special comment appears inside string literal.
    61  		{`// Package p doc.
    62  package p
    63  const c = "` + "`" + `
    64  // Code generated by gen. DO NOT EDIT.
    65  ` + "`" + `
    66  `, false},
    67  		// Special comment appears properly.
    68  		{`// Copyright 2019 The Go Authors. All rights reserved.
    69  // Use of this source code is governed by a BSD-style
    70  // license that can be found in the LICENSE file.
    71  
    72  // Package p doc comment goes here.
    73  //
    74  // Code generated by gen. DO NOT EDIT.
    75  package p
    76  
    77  ... `, true},
    78  		// Special comment is indented.
    79  		//
    80  		// Strictly, the indent should cause IsGenerated to
    81  		// yield false, but we cannot detect the indent
    82  		// without either source text or a token.File.
    83  		// In other words, the function signature cannot
    84  		// implement the spec. Let's brush this under the
    85  		// rug since well-formatted code has no indent.
    86  		{`// Package p doc comment goes here.
    87  //
    88  	// Code generated by gen. DO NOT EDIT.
    89  package p
    90  
    91  ... `, true},
    92  		// Special comment has unwanted spaces after "DO NOT EDIT."
    93  		{`// Copyright 2019 The Go Authors. All rights reserved.
    94  // Use of this source code is governed by a BSD-style
    95  // license that can be found in the LICENSE file.
    96  
    97  // Package p doc comment goes here.
    98  //
    99  // Code generated by gen. DO NOT EDIT. 
   100  package p
   101  
   102  ... `, false},
   103  		// Special comment has rogue interior space.
   104  		{`//     Code generated by gen. DO NOT EDIT.
   105  package p
   106  `, false},
   107  		// Special comment lacks the middle portion.
   108  		{`// Code generated DO NOT EDIT.
   109  package p
   110  `, false},
   111  		// Special comment (incl. "//") appears within a /* block */ comment,
   112  		// an obscure corner case of the spec.
   113  		{`/* start of a general comment
   114  
   115  // Code generated by tool; DO NOT EDIT.
   116  
   117  end of a general comment */
   118  
   119  // +build !dev
   120  
   121  // Package comment.
   122  package p
   123  
   124  // Does match even though it's inside general comment (/*-style).
   125  `, true},
   126  	} {
   127  		fset := token.NewFileSet()
   128  		f, err := parser.ParseFile(fset, "", test.src, parser.PackageClauseOnly|parser.ParseComments)
   129  		if f == nil {
   130  			t.Fatalf("parse %d failed to return AST: %v", i, err)
   131  		}
   132  
   133  		got := ast.IsGenerated(f)
   134  		if got != test.want {
   135  			t.Errorf("%d: IsGenerated on <<%s>> returned %t", i, test.src, got)
   136  		}
   137  	}
   138  
   139  }
   140
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