contrib/olivere/elastic: fix ineffectual assignment #1010
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`snip, err = ioutil.ReadAll(gzr)` was ineffectual assignment.
| gzr, err := gzip.NewReader(bytes.NewReader(snip)) | ||
| if err != nil { | ||
| gzr, err2 := gzip.NewReader(bytes.NewReader(snip)) | ||
| if err2 != nil { |
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@mrkm4ntr maybe I haven't had enough coffee yet, but I don't understand why the previous assignment would have been "ineffectual"? See https://play.golang.org/p/hUfSbzBrIoG
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Actual ineffectual assignment is here.
The scope of err is in this block. So I changed the name of err in this scope to err2.
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I don't see how this changes the logic. Whether the variable is named err or err2, it is block-scoped and never used outside the block. Likewise, we're not using the outer err inside the block, so shadowing is not an issue.
If there is a bug here, please add a test that exposes the bug which is fixed by this change.
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Again, the problematic part is here.
dd-trace-go/contrib/olivere/elastic/elastictrace.go
Lines 143 to 145 in f86a82b
if
ioutil.ReadAll(gzr) returns error, that error is assigned to scoped err not err that function returns. So this function cannot return error of ioutil.ReadAll(gzr).
The test is still required...? I think it is preferred to introduce linters to detect these kind of bugs automatically.
https://github.com/gordonklaus/ineffassign
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@mrkm4ntr Thank you for the clarification. I did not look closely enough my first time through.
A test case is always welcome, but I think we can merge this as-is.
| gzr, err := gzip.NewReader(bytes.NewReader(snip)) | ||
| if err != nil { | ||
| gzr, err2 := gzip.NewReader(bytes.NewReader(snip)) | ||
| if err2 != nil { |
| gzr, err := gzip.NewReader(bytes.NewReader(snip)) | ||
| if err != nil { | ||
| gzr, err2 := gzip.NewReader(bytes.NewReader(snip)) | ||
| if err2 != nil { |
There was a problem hiding this comment.
I don't see how this changes the logic. Whether the variable is named err or err2, it is block-scoped and never used outside the block. Likewise, we're not using the outer err inside the block, so shadowing is not an issue.
If there is a bug here, please add a test that exposes the bug which is fixed by this change.
| gzr, err := gzip.NewReader(bytes.NewReader(snip)) | ||
| if err != nil { | ||
| gzr, err2 := gzip.NewReader(bytes.NewReader(snip)) | ||
| if err2 != nil { |
There was a problem hiding this comment.
@mrkm4ntr Thank you for the clarification. I did not look closely enough my first time through.
A test case is always welcome, but I think we can merge this as-is.
knusbaum
changed the title
snip, err = ioutil.ReadAll(gzr)was ineffectual assignment.