Check for redundant if err != nil constructs. (#319)

* Check for redundant if err != nil constructs.

Detect and complain about constructs like:

if err := foo(); err != nil {
  return err
}
return nil

(Issue https://github.com/golang/lint/issues/312)

* Rewrite lintIfError without using matchers.

Also don't emit lint errors if there are any comments explaining the
construct (between if and return statements).
2 files changed
tree: a72ed32c9eda0203341e680f2da99d41c3cc45a0
  1. golint/
  2. misc/
  3. testdata/
  4. .travis.yml
  5. CONTRIBUTING.md
  6. LICENSE
  7. lint.go
  8. lint_test.go
  9. README.md
README.md

Golint is a linter for Go source code.

Build Status

Installation

Golint requires Go 1.6 or later.

go get -u github.com/golang/lint/golint

Usage

Invoke golint with one or more filenames, directories, or packages named by its import path. Golint uses the same import path syntax as the go command and therefore also supports relative import paths like ./.... Additionally the ... wildcard can be used as suffix on relative and absolute file paths to recurse into them.

The output of this tool is a list of suggestions in Vim quickfix format, which is accepted by lots of different editors.

Purpose

Golint differs from gofmt. Gofmt reformats Go source code, whereas golint prints out style mistakes.

Golint differs from govet. Govet is concerned with correctness, whereas golint is concerned with coding style. Golint is in use at Google, and it seeks to match the accepted style of the open source Go project.

The suggestions made by golint are exactly that: suggestions. Golint is not perfect, and has both false positives and false negatives. Do not treat its output as a gold standard. We will not be adding pragmas or other knobs to suppress specific warnings, so do not expect or require code to be completely “lint-free”. In short, this tool is not, and will never be, trustworthy enough for its suggestions to be enforced automatically, for example as part of a build process. Golint makes suggestions for many of the mechanically checkable items listed in Effective Go and the CodeReviewComments wiki page.

If you find an established style that is frequently violated, and which you think golint could statically check, file an issue.

Contributions

Contributions to this project are welcome, though please send mail before starting work on anything major. Contributors retain their copyright, so we need you to fill out a short form before we can accept your contribution.

Vim

Add this to your ~/.vimrc:

set rtp+=$GOPATH/src/github.com/golang/lint/misc/vim

If you have multiple entries in your GOPATH, replace $GOPATH with the right value.

Running :Lint will run golint on the current file and populate the quickfix list.

Optionally, add this to your ~/.vimrc to automatically run golint on :w

autocmd BufWritePost,FileWritePost *.go execute 'Lint' | cwindow

Emacs

Add this to your .emacs file:

(add-to-list 'load-path (concat (getenv "GOPATH")  "/src/github.com/golang/lint/misc/emacs"))
(require 'golint)

If you have multiple entries in your GOPATH, replace $GOPATH with the right value.

Running M-x golint will run golint on the current file.

For more usage, see Compilation-Mode.