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, 343 insertions, 0 deletions

diff --git a/src/cmd/doc/doc_test.go b/src/cmd/doc/doc_test.go
new file mode 100644
index 0000000000..0936d4d2d4
--- /dev/null
+++ b/src/cmd/doc/doc_test.go
@@ -0,0 +1,343 @@
+// 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 main
+
+import (
+	"bytes"
+	"flag"
+	"os"
+	"os/exec"
+	"regexp"
+	"testing"
+)
+
+const (
+	dataDir = "testdata"
+	binary  = "testdoc"
+)
+
+type test struct {
+	name string
+	args []string // Arguments to "[go] doc".
+	yes  []string // Regular expressions that should match.
+	no   []string // Regular expressions that should not match.
+}
+
+const p = "cmd/doc/testdata"
+
+var tests = []test{
+	// Sanity check.
+	{
+		"fmt",
+		[]string{`fmt`},
+		[]string{`type Formatter interface`},
+		nil,
+	},
+
+	// Package dump includes import, package statement.
+	{
+		"package clause",
+		[]string{p},
+		[]string{`package pkg.*cmd/doc/testdata`},
+		nil,
+	},
+
+	// Constants.
+	// Package dump
+	{
+		"full package",
+		[]string{p},
+		[]string{
+			`Package comment`,
+			`const ExportedConstant = 1`,                            // Simple constant.
+			`ConstOne = 1`,                                          // First entry in constant block.
+			`const ExportedVariable = 1`,                            // Simple variable.
+			`VarOne = 1`,                                            // First entry in variable block.
+			`func ExportedFunc\(a int\) bool`,                       // Function.
+			`type ExportedType struct { ... }`,                      // Exported type.
+			`const ExportedTypedConstant ExportedType = iota`,       // Typed constant.
+			`const ExportedTypedConstant_unexported unexportedType`, // Typed constant, exported for unexported type.
+		},
+		[]string{
+			`const internalConstant = 2`,        // No internal constants.
+			`const internalVariable = 2`,        // No internal variables.
+			`func internalFunc(a int) bool`,     // No internal functions.
+			`Comment about exported constant`,   // No comment for single constant.
+			`Comment about exported variable`,   // No comment for single variable.
+			`Comment about block of constants.`, // No comment for constant block.
+			`Comment about block of variables.`, // No comment for variable block.
+			`Comment before ConstOne`,           // No comment for first entry in constant block.
+			`Comment before VarOne`,             // No comment for first entry in variable block.
+			`ConstTwo = 2`,                      // No second entry in constant block.
+			`VarTwo = 2`,                        // No second entry in variable block.
+			`type unexportedType`,               // No unexported type.
+			`unexportedTypedConstant`,           // No unexported typed constant.
+			`Field`,                             // No fields.
+			`Method`,                            // No methods.
+		},
+	},
+	// Package dump -u
+	{
+		"full package with u",
+		[]string{`-u`, p},
+		[]string{
+			`const ExportedConstant = 1`,      // Simple constant.
+			`const internalConstant = 2`,      // Internal constants.
+			`func internalFunc\(a int\) bool`, // Internal functions.
+		},
+		[]string{
+			`Comment about exported constant`,  // No comment for simple constant.
+			`Comment about block of constants`, // No comment for constant block.
+			`Comment about internal function`,  // No comment for internal function.
+		},
+	},
+
+	// Single constant.
+	{
+		"single constant",
+		[]string{p, `ExportedConstant`},
+		[]string{
+			`Comment about exported constant`, // Include comment.
+			`const ExportedConstant = 1`,
+		},
+		nil,
+	},
+	// Single constant -u.
+	{
+		"single constant with -u",
+		[]string{`-u`, p, `internalConstant`},
+		[]string{
+			`Comment about internal constant`, // Include comment.
+			`const internalConstant = 2`,
+		},
+		nil,
+	},
+	// Block of constants.
+	{
+		"block of constants",
+		[]string{p, `ConstTwo`},
+		[]string{
+			`Comment before ConstOne.\n.*ConstOne = 1`,    // First...
+			`ConstTwo = 2.*Comment on line with ConstTwo`, // And second show up.
+			`Comment about block of constants`,            // Comment does too.
+		},
+		[]string{
+			`constThree`, // No unexported constant.
+		},
+	},
+	// Block of constants -u.
+	{
+		"block of constants with -u",
+		[]string{"-u", p, `constThree`},
+		[]string{
+			`constThree = 3.*Comment on line with constThree`,
+		},
+		nil,
+	},
+
+	// Single variable.
+	{
+		"single variable",
+		[]string{p, `ExportedVariable`},
+		[]string{
+			`ExportedVariable`, // Include comment.
+			`const ExportedVariable = 1`,
+		},
+		nil,
+	},
+	// Single variable -u.
+	{
+		"single variable with -u",
+		[]string{`-u`, p, `internalVariable`},
+		[]string{
+			`Comment about internal variable`, // Include comment.
+			`const internalVariable = 2`,
+		},
+		nil,
+	},
+	// Block of variables.
+	{
+		"block of variables",
+		[]string{p, `VarTwo`},
+		[]string{
+			`Comment before VarOne.\n.*VarOne = 1`,    // First...
+			`VarTwo = 2.*Comment on line with VarTwo`, // And second show up.
+			`Comment about block of variables`,        // Comment does too.
+		},
+		[]string{
+			`varThree= 3`, // No unexported variable.
+		},
+	},
+	// Block of variables -u.
+	{
+		"block of variables with -u",
+		[]string{"-u", p, `varThree`},
+		[]string{
+			`varThree = 3.*Comment on line with varThree`,
+		},
+		nil,
+	},
+
+	// Function.
+	{
+		"function",
+		[]string{p, `ExportedFunc`},
+		[]string{
+			`Comment about exported function`, // Include comment.
+			`func ExportedFunc\(a int\) bool`,
+		},
+		nil,
+	},
+	// Function -u.
+	{
+		"function with -u",
+		[]string{"-u", p, `internalFunc`},
+		[]string{
+			`Comment about internal function`, // Include comment.
+			`func internalFunc\(a int\) bool`,
+		},
+		nil,
+	},
+
+	// Type.
+	{
+		"type",
+		[]string{p, `ExportedType`},
+		[]string{
+			`Comment about exported type`, // Include comment.
+			`type ExportedType struct`,    // Type definition.
+			`Comment before exported field.*\n.*ExportedField +int`,
+			`Has unexported fields`,
+			`func \(ExportedType\) ExportedMethod\(a int\) bool`,
+			`const ExportedTypedConstant ExportedType = iota`, // Must include associated constant.
+		},
+		[]string{
+			`unexportedField`,                // No unexported field.
+			`Comment about exported method.`, // No comment about exported method.
+			`unexportedMethod`,               // No unexported method.
+			`unexportedTypedConstant`,        // No unexported constant.
+		},
+	},
+	// Type -u with unexported fields.
+	{
+		"type with unexported fields and -u",
+		[]string{"-u", p, `ExportedType`},
+		[]string{
+			`Comment about exported type`, // Include comment.
+			`type ExportedType struct`,    // Type definition.
+			`Comment before exported field.*\n.*ExportedField +int`,
+			`unexportedField int.*Comment on line with unexported field.`,
+			`func \(ExportedType\) unexportedMethod\(a int\) bool`,
+			`unexportedTypedConstant`,
+		},
+		[]string{
+			`Has unexported fields`,
+		},
+	},
+	// Unexported type with -u.
+	{
+		"unexported type with -u",
+		[]string{"-u", p, `unexportedType`},
+		[]string{
+			`Comment about unexported type`, // Include comment.
+			`type unexportedType int`,       // Type definition.
+			`func \(unexportedType\) ExportedMethod\(\) bool`,
+			`func \(unexportedType\) unexportedMethod\(\) bool`,
+			`ExportedTypedConstant_unexported unexportedType = iota`,
+			`const unexportedTypedConstant unexportedType = 1`,
+		},
+		nil,
+	},
+
+	// Method.
+	{
+		"method",
+		[]string{p, `ExportedType.ExportedMethod`},
+		[]string{
+			`func \(ExportedType\) ExportedMethod\(a int\) bool`,
+			`Comment about exported method.`,
+		},
+		nil,
+	},
+	// Method  with -u.
+	{
+		"method with -u",
+		[]string{"-u", p, `ExportedType.unexportedMethod`},
+		[]string{
+			`func \(ExportedType\) unexportedMethod\(a int\) bool`,
+			`Comment about unexported method.`,
+		},
+		nil,
+	},
+
+	// Case matching off.
+	{
+		"case matching off",
+		[]string{p, `casematch`},
+		[]string{
+			`CaseMatch`,
+			`Casematch`,
+		},
+		nil,
+	},
+
+	// Case matching on.
+	{
+		"case matching on",
+		[]string{"-c", p, `Casematch`},
+		[]string{
+			`Casematch`,
+		},
+		[]string{
+			`CaseMatch`,
+		},
+	},
+}
+
+func TestDoc(t *testing.T) {
+	for _, test := range tests {
+		var b bytes.Buffer
+		var flagSet flag.FlagSet
+		err := do(&b, &flagSet, test.args)
+		if err != nil {
+			t.Fatalf("%s: %s\n", test.name, err)
+		}
+		output := b.Bytes()
+		failed := false
+		for j, yes := range test.yes {
+			re, err := regexp.Compile(yes)
+			if err != nil {
+				t.Fatalf("%s.%d: compiling %#q: %s", test.name, j, yes, err)
+			}
+			if !re.Match(output) {
+				t.Errorf("%s.%d: no match for %s %#q", test.name, j, test.args, yes)
+				failed = true
+			}
+		}
+		for j, no := range test.no {
+			re, err := regexp.Compile(no)
+			if err != nil {
+				t.Fatalf("%s.%d: compiling %#q: %s", test.name, j, no, err)
+			}
+			if re.Match(output) {
+				t.Errorf("%s.%d: incorrect match for %s %#q", test.name, j, test.args, no)
+				failed = true
+			}
+		}
+		if failed {
+			t.Logf("\n%s", output)
+		}
+	}
+}
+
+// run runs the command, but calls t.Fatal if there is an error.
+func run(c *exec.Cmd, t *testing.T) []byte {
+	output, err := c.CombinedOutput()
+	if err != nil {
+		os.Stdout.Write(output)
+		t.Fatal(err)
+	}
+	return output
+}