cmd/doc: add test

Refactor main a bit to make it possible to run tests without an exec every time.
(Makes a huge difference in run time.)

Add a silver test. Not quite golden, since it looks for pieces rather than the
full output, and also includes tests for what should not appear.

Fixes #10920.

Change-Id: I6a4951cc14e61763379754a10b0cc3484d30c267
Reviewed-on: https://go-review.googlesource.com/11272
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Rob Pike <r@golang.org>

1 files changed, 91 insertions, 0 deletions

diff --git a/src/cmd/doc/testdata/pkg.go b/src/cmd/doc/testdata/pkg.go
new file mode 100644
index 0000000000..ccc2ed64e0
--- /dev/null
+++ b/src/cmd/doc/testdata/pkg.go
@@ -0,0 +1,91 @@
+// Copyright 2015 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 comment.
+package pkg
+
+// Constants
+
+// Comment about exported constant.
+const ExportedConstant = 1
+
+// Comment about internal constant.
+const internalConstant = 2
+
+// Comment about block of constants.
+const (
+	// Comment before ConstOne.
+	ConstOne   = 1
+	ConstTwo   = 2 // Comment on line with ConstTwo.
+	constThree = 3 // Comment on line with constThree.
+)
+
+// Variables
+
+// Comment about exported variable.
+const ExportedVariable = 1
+
+// Comment about internal variable.
+const internalVariable = 2
+
+// Comment about block of variables.
+const (
+	// Comment before VarOne.
+	VarOne   = 1
+	VarTwo   = 2 // Comment on line with VarTwo.
+	varThree = 3 // Comment on line with varThree.
+)
+
+// Comment about exported function.
+func ExportedFunc(a int) bool
+
+// Comment about internal function.
+func internalFunc(a int) bool
+
+// Comment about exported type.
+type ExportedType struct {
+	// Comment before exported field.
+	ExportedField   int
+	unexportedField int // Comment on line with unexported field.
+}
+
+// Comment about exported method.
+func (ExportedType) ExportedMethod(a int) bool {
+	return true
+}
+
+// Comment about unexported method.
+func (ExportedType) unexportedMethod(a int) bool {
+	return true
+}
+
+// Constants tied to ExportedType. (The type is a struct so this isn't valid Go,
+// but it parses and that's all we need.)
+const (
+	ExportedTypedConstant ExportedType = iota
+)
+
+const unexportedTypedConstant ExportedType = 1 // In a separate section to test -u.
+
+// Comment about unexported type.
+type unexportedType int
+
+func (unexportedType) ExportedMethod() bool {
+	return true
+}
+
+func (unexportedType) unexportedMethod() bool {
+	return true
+}
+
+// Constants tied to unexportedType.
+const (
+	ExportedTypedConstant_unexported unexportedType = iota
+)
+
+const unexportedTypedConstant unexportedType = 1 // In a separate section to test -u.
+
+// For case matching.
+const CaseMatch = 1
+const Casematch = 2