codekingpro/portable-devtools

1// Copyright 2012 The Go Authors. All rights reserved.2// Use of this source code is governed by a BSD-style3// license that can be found in the LICENSE file.4 5package format6 7import (8	"bytes"9	"go/ast"10	"go/parser"11	"go/token"12	"os"13	"strings"14	"testing"15)16 17const testfile = "format_test.go"18 19func diff(t *testing.T, dst, src []byte) {20	line := 121	offs := 0 // line offset22	for i := 0; i < len(dst) && i < len(src); i++ {23		d := dst[i]24		s := src[i]25		if d != s {26			t.Errorf("dst:%d: %s\n", line, dst[offs:i+1])27			t.Errorf("src:%d: %s\n", line, src[offs:i+1])28			return29		}30		if s == '\n' {31			line++32			offs = i + 133		}34	}35	if len(dst) != len(src) {36		t.Errorf("len(dst) = %d, len(src) = %d\nsrc = %q", len(dst), len(src), src)37	}38}39 40func TestNode(t *testing.T) {41	src, err := os.ReadFile(testfile)42	if err != nil {43		t.Fatal(err)44	}45 46	fset := token.NewFileSet()47	file, err := parser.ParseFile(fset, testfile, src, parser.ParseComments)48	if err != nil {49		t.Fatal(err)50	}51 52	var buf bytes.Buffer53 54	if err = Node(&buf, fset, file); err != nil {55		t.Fatal("Node failed:", err)56	}57 58	diff(t, buf.Bytes(), src)59}60 61// Node is documented to not modify the AST.62// Test that it is so even when numbers are normalized.63func TestNodeNoModify(t *testing.T) {64	const (65		src    = "package p\n\nconst _ = 0000000123i\n"66		golden = "package p\n\nconst _ = 123i\n"67	)68 69	fset := token.NewFileSet()70	file, err := parser.ParseFile(fset, "", src, parser.ParseComments)71	if err != nil {72		t.Fatal(err)73	}74 75	// Capture original address and value of a BasicLit node76	// which will undergo formatting changes during printing.77	wantLit := file.Decls[0].(*ast.GenDecl).Specs[0].(*ast.ValueSpec).Values[0].(*ast.BasicLit)78	wantVal := wantLit.Value79 80	var buf bytes.Buffer81	if err = Node(&buf, fset, file); err != nil {82		t.Fatal("Node failed:", err)83	}84	diff(t, buf.Bytes(), []byte(golden))85 86	// Check if anything changed after Node returned.87	gotLit := file.Decls[0].(*ast.GenDecl).Specs[0].(*ast.ValueSpec).Values[0].(*ast.BasicLit)88	gotVal := gotLit.Value89 90	if gotLit != wantLit {91		t.Errorf("got *ast.BasicLit address %p, want %p", gotLit, wantLit)92	}93	if gotVal != wantVal {94		t.Errorf("got *ast.BasicLit value %q, want %q", gotVal, wantVal)95	}96}97 98func TestSource(t *testing.T) {99	src, err := os.ReadFile(testfile)100	if err != nil {101		t.Fatal(err)102	}103 104	res, err := Source(src)105	if err != nil {106		t.Fatal("Source failed:", err)107	}108 109	diff(t, res, src)110}111 112// Test cases that are expected to fail are marked by the prefix "ERROR".113// The formatted result must look the same as the input for successful tests.114var tests = []string{115	// declaration lists116	`import "go/format"`,117	"var x int",118	"var x int\n\ntype T struct{}",119 120	// statement lists121	"x := 0",122	"f(a, b, c)\nvar x int = f(1, 2, 3)",123 124	// indentation, leading and trailing space125	"\tx := 0\n\tgo f()",126	"\tx := 0\n\tgo f()\n\n\n",127	"\n\t\t\n\n\tx := 0\n\tgo f()\n\n\n",128	"\n\t\t\n\n\t\t\tx := 0\n\t\t\tgo f()\n\n\n",129	"\n\t\t\n\n\t\t\tx := 0\n\t\t\tconst s = `\nfoo\n`\n\n\n",     // no indentation added inside raw strings130	"\n\t\t\n\n\t\t\tx := 0\n\t\t\tconst s = `\n\t\tfoo\n`\n\n\n", // no indentation removed inside raw strings131 132	// comments133	"/* Comment */",134	"\t/* Comment */ ",135	"\n/* Comment */ ",136	"i := 5 /* Comment */",         // issue #5551137	"\ta()\n//line :1",             // issue #11276138	"\t//xxx\n\ta()\n//line :2",    // issue #11276139	"\ta() //line :1\n\tb()\n",     // issue #11276140	"x := 0\n//line :1\n//line :2", // issue #11276141 142	// whitespace143	"",     // issue #11275144	" ",    // issue #11275145	"\t",   // issue #11275146	"\t\t", // issue #11275147	"\n",   // issue #11275148	"\n\n", // issue #11275149	"\t\n", // issue #11275150 151	// erroneous programs152	"ERROR1 + 2 +",153	"ERRORx :=  0",154 155	// build comments156	"// copyright\n\n//go:build x\n\npackage p\n",157	"// copyright\n\n//go:build x\n// +build x\n\npackage p\n",158}159 160func String(s string) (string, error) {161	res, err := Source([]byte(s))162	if err != nil {163		return "", err164	}165	return string(res), nil166}167 168func TestPartial(t *testing.T) {169	for _, src := range tests {170		if strings.HasPrefix(src, "ERROR") {171			// test expected to fail172			src = src[5:] // remove ERROR prefix173			res, err := String(src)174			if err == nil && res == src {175				t.Errorf("formatting succeeded but was expected to fail:\n%q", src)176			}177		} else {178			// test expected to succeed179			res, err := String(src)180			if err != nil {181				t.Errorf("formatting failed (%s):\n%q", err, src)182			} else if res != src {183				t.Errorf("formatting incorrect:\nsource: %q\nresult: %q", src, res)184			}185		}186	}187}188