graph: imported graph as a subtree

graph/formats/dot/internal/lexer/lexer_test.go

@@ -0,0 +1,54 @@
+// This file is dual licensed under CC0 and The gonum license.
+//
+// Copyright ©2017 The gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// Copyright ©2017 Robin Eklind.
+// This file is made available under a Creative Commons CC0 1.0
+// Universal Public Domain Dedication.
+
+package lexer_test
+
+import (
+	"bytes"
+	"io/ioutil"
+	"testing"
+
+	"github.com/gonum/graph/formats/dot"
+)
+
+func TestParseFile(t *testing.T) {
+	golden := []struct {
+		in  string
+		out string
+	}{
+		{
+			in:  "testdata/tokens.dot",
+			out: "testdata/tokens.golden",
+		},
+	}
+	for _, g := range golden {
+		file, err := dot.ParseFile(g.in)
+		if err != nil {
+			t.Errorf("%q: unable to parse file; %v", g.in, err)
+			continue
+		}
+		// If no output path is specified, the input is already golden.
+		out := g.in
+		if len(g.out) > 0 {
+			out = g.out
+		}
+		buf, err := ioutil.ReadFile(out)
+		if err != nil {
+			t.Errorf("%q: unable to read file; %v", g.in, err)
+			continue
+		}
+		got := file.String()
+		// Remove trailing newline.
+		want := string(bytes.TrimSpace(buf))
+		if got != want {
+			t.Errorf("%q: graph mismatch; expected %q, got %q", g.in, want, got)
+		}
+	}
+}