printer_test: first cut

R=rsc
DELTA=169  (168 added, 0 deleted, 1 changed)
OCL=31319
CL=31321

src/pkg/go/printer/Makefile

@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style
 # license that can be found in the LICENSE file.
 
+
 # DO NOT EDIT.  Automatically generated by gobuild.
 # gobuild -m >Makefile
 
@@ -20,7 +21,7 @@ test: packages
 
 coverage: packages
 	gotest
-	6cov -g `pwd` | grep -v '_test\.go:'
+	6cov -g $$(pwd) | grep -v '_test\.go:'
 
 %.$O: %.go
 	$(GC) -I_obj $*.go

src/pkg/go/printer/data/golden1.go

@@ -0,0 +1,25 @@
+package main
+
+import  "fmt" // fmt
+
+const c0 = 0 // zero
+
+const (
+    c1  = iota; // c1
+    c2  // c2
+)
+
+type T struct {
+    a, b, c int // 3 fields
+}
+
+var x int // x
+
+var ()
+
+func f0() {
+    const pi = 3.14;
+    var s1 struct {}
+    var s2 struct {} = struct {}{};
+    x := pi
+}

src/pkg/go/printer/data/golden1.x

@@ -0,0 +1,3 @@
+package main
+
+type T struct

src/pkg/go/printer/data/source1.go

@@ -0,0 +1,26 @@
+package main
+
+import "fmt"  // fmt
+
+const c0 = 0;  // zero
+const (
+	c1 = iota;  // c1
+	c2;  // c2
+)
+
+
+type T struct {
+	a, b, c int  // 3 fields
+}
+
+
+var x int;  // x
+var ()
+
+
+func f0() {
+	const pi = 3.14;  // pi
+	var s1 struct {}
+	var s2 struct {} = struct {}{};
+	x := pi;
+}

src/pkg/go/printer/printer_test.go

@@ -0,0 +1,114 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package printer
+
+import (
+	"bytes";
+	"io";
+	"go/ast";
+	"go/parser";
+	"go/printer";
+	"os";
+	"path";
+	"tabwriter";
+	"testing";
+)
+
+
+const (
+	tabwidth = 4;
+	padding = 1;
+	tabchar = ' ';
+)
+
+
+func lineString(text []byte, i int) string {
+	i0 := i;
+	for i < len(text) && text[i] != '\n' {
+		i++;
+	}
+	return string(text[i0 : i]);
+}
+
+
+func check(t *testing.T, source, golden string, exports bool) {
+	// get source
+	src, err := io.ReadFile(source);
+	if err != nil {
+		t.Error(err);
+		return;
+	}
+
+	// parse source
+	prog, err := parser.Parse(src, parser.ParseComments);
+	if err != nil {
+		t.Error(err);
+		return;
+	}
+
+	// filter exports if necessary
+	if exports {
+		ast.FilterExports(prog);  // ignore result
+	}
+
+	// format source
+	var buf bytes.Buffer;
+	w := tabwriter.NewWriter(&buf, tabwidth, padding, tabchar, 0);
+	Fprint(w, prog, 0);
+	w.Flush();
+	res := buf.Data();
+
+	// get golden
+	gld, err := io.ReadFile(golden);
+	if err != nil {
+		t.Error(err);
+		return;
+	}
+
+	// compare lengths
+	if len(res) != len(gld) {
+		t.Errorf("len = %d, expected %d (= len(%s))", len(res), len(gld), golden);
+	}
+
+	// compare contents
+	for i, line, offs := 0, 1, 0; i < len(res) && i < len(gld); i++ {
+		ch := res[i];
+		if ch != gld[i] {
+			t.Errorf("%s:%d:%d: %s", source, line, i-offs+1, lineString(res, offs));
+			t.Errorf("%s:%d:%d: %s", golden, line, i-offs+1, lineString(gld, offs));
+			t.Error();
+			return;
+		}
+		if ch == '\n' {
+			line++;
+			offs = i+1;
+		}
+	}
+}
+
+
+const dataDir = "data";
+
+type entry struct {
+	source, golden string;
+	exports bool;
+}
+
+// Use gofmt to create/update the respective golden files:
+//
+//   gofmt source.go > golden.go
+//   gofmt -x source.go > golden.x
+//
+var data = []entry{
+	entry{ "source1.go", "golden1.go", false },
+	entry{ "source1.go", "golden1.x", true },
+}
+
+
+func Test(t *testing.T) {
+	for _, e := range data {
+		check(t, path.Join(dataDir, e.source), path.Join(dataDir, e.golden), e.exports);
+	}
+}