code review 7071050: testing: in example, empty output not distinguished fro...

testing: in example, empty output not distinguished from missing output

Fixes issue 4485.

[ryanslade, 2013-01-08 12:43:10]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go/

[rsc, 2013-01-09 19:11:18]

This changes the interpretation of Example structs that don't set
HasOutput. That is, Example{Output:"foo"} right now means to expect
"foo" but after this CL it will not mean that anymore. It might be
that no one uses this type, but we don't know that, and it's a good
habit not to make semantic changes, to try to respect the Go 1
contract.

I suggest instead:
    EmptyOutput bool // expect empty output

Russ

[ryanslade, 2013-01-10 13:00:52]

Hello golang-dev@googlegroups.com, rsc@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[ryanslade, 2013-01-10 13:01:59]

Hello golang-dev@googlegroups.com, rsc@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[adg, 2013-01-11 03:10:36]

https://codereview.appspot.com/7071050/diff/8001/src/cmd/go/test.go
File src/cmd/go/test.go (right):

https://codereview.appspot.com/7071050/diff/8001/src/cmd/go/test.go#newcode795
src/cmd/go/test.go:795: if e.EmptyOutput {
if e.Output == "" && !e.EmptyOutput {

https://codereview.appspot.com/7071050/diff/8001/src/pkg/go/doc/example.go
File src/pkg/go/doc/example.go (right):

https://codereview.appspot.com/7071050/diff/8001/src/pkg/go/doc/example.go#ne...
src/pkg/go/doc/example.go:59: output, emptyOutput := exampleOutput(f.Body,
file.Comments)
output, hasOutput := exampleOutput...

https://codereview.appspot.com/7071050/diff/8001/src/pkg/go/doc/example.go#ne...
src/pkg/go/doc/example.go:67: EmptyOutput: emptyOutput,
output == "" && hasOutput

https://codereview.appspot.com/7071050/diff/8001/src/pkg/go/doc/example.go#ne...
src/pkg/go/doc/example.go:86: func exampleOutput(b *ast.BlockStmt, comments
[]*ast.CommentGroup) (string, bool) {
the return values should be (output string, ok bool) 

and the meaning of the bool should be the opposite of what you have here; true
means that a comment was found, false means one was not

[ryanslade, 2013-01-11 12:10:31]

I've made the changes as suggested

https://codereview.appspot.com/7071050/diff/8001/src/cmd/go/test.go
File src/cmd/go/test.go (right):

https://codereview.appspot.com/7071050/diff/8001/src/cmd/go/test.go#newcode795
src/cmd/go/test.go:795: if e.EmptyOutput {
On 2013/01/11 03:10:37, adg wrote:
> if e.Output == "" && !e.EmptyOutput {

Done.

https://codereview.appspot.com/7071050/diff/8001/src/pkg/go/doc/example.go
File src/pkg/go/doc/example.go (right):

https://codereview.appspot.com/7071050/diff/8001/src/pkg/go/doc/example.go#ne...
src/pkg/go/doc/example.go:59: output, emptyOutput := exampleOutput(f.Body,
file.Comments)
On 2013/01/11 03:10:37, adg wrote:
> output, hasOutput := exampleOutput...

Done.

https://codereview.appspot.com/7071050/diff/8001/src/pkg/go/doc/example.go#ne...
src/pkg/go/doc/example.go:67: EmptyOutput: emptyOutput,
On 2013/01/11 03:10:37, adg wrote:
> output == "" && hasOutput

Done.

https://codereview.appspot.com/7071050/diff/8001/src/pkg/go/doc/example.go#ne...
src/pkg/go/doc/example.go:86: func exampleOutput(b *ast.BlockStmt, comments
[]*ast.CommentGroup) (string, bool) {
On 2013/01/11 03:10:37, adg wrote:
> the return values should be (output string, ok bool) 
> 
> and the meaning of the bool should be the opposite of what you have here; true
> means that a comment was found, false means one was not

Done.

[ryanslade, 2013-01-11 12:11:01]

Hello golang-dev@googlegroups.com, rsc@golang.org, adg@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[ryanslade, 2013-01-11 12:17:41]

Hello golang-dev@googlegroups.com, rsc@golang.org, adg@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[adg, 2013-01-12 00:05:35]

LGTM

[adg, 2013-01-12 00:06:01]

*** Submitted as https://code.google.com/p/go/source/detail?r=97e9dac9a01d ***

testing: in example, empty output not distinguished from missing output

Fixes issue 4485.

R=golang-dev, rsc, adg
CC=golang-dev
https://codereview.appspot.com/7071050

Committer: Andrew Gerrand <adg@golang.org>