false-positives.mdx

title
False Positives

False positives are inevitable, but we did our best to reduce their count. For example, we have a default enabled set of exclude patterns.

If a false positive occurred, you have the several choices.

Specific Linter Excludes

Most of the linters has a configuration, sometimes false-positives can be related to a bad configuration of a linter. So it's recommended to check the linters configuration.

Otherwise, some linters have dedicated configuration to exclude or disable rules.

An example with staticcheck:

linters-settings:
  staticcheck:
    checks:
      - all
      - '-SA1000' # disable the rule SA1000
      - '-SA1004' # disable the rule SA1004

Exclude or Skip

Exclude Issue by Text

Exclude issue by text using command-line option -e or config option issues.exclude. It's helpful when you decided to ignore all issues of this type. Also, you can use issues.exclude-rules config option for per-path or per-linter configuration.

In the following example, all the reports that contains the sentences defined in exclude are excluded:

issues:
  exclude:
    - "Error return value of .((os\\.)?std(out|err)\\..*|.*Close|.*Flush|os\\.Remove(All)?|.*printf?|os\\.(Un)?Setenv). is not checked"
    - "exported (type|method|function) (.+) should have comment or be unexported"
    - "ST1000: at least one file in a package should have a package comment"

In the following example, all the reports from the linters (linters) that contains the text (text) are excluded:

issues:
  exclude-rules:
    - linters:
        - gomnd
      text: "mnd: Magic number: 9"

In the following example, all the reports that contains the text (text) in the path (path) are excluded:

issues:
  exclude-rules:
    - path: path/to/a/file.go
      text: "string `example` has (\\d+) occurrences, make it a constant"

Exclude Issues by Path

Exclude issues in path by run.skip-dirs, run.skip-files or issues.exclude-rules config options.

Beware that the paths that get matched here are relative to the current working directory. When the configuration contains path patterns that check for specific directories, the --path-prefix parameter can be used to extend the paths before matching.

In the following example, all the reports from the linters (linters) that concerns the path (path) are excluded:

issues:
  exclude-rules:
    - path: '(.+)_test\.go'
      linters:
        - funlen
        - goconst

In the following example, all the reports related to the files (skip-files) are excluded:

run:
  skip-files:
    - path/to/a/file.go

In the following example, all the reports related to the directories (skip-dirs) are excluded:

run:
  skip-dirs:
    - path/to/a/dir/

Nolint Directive

To exclude issues from all linters use //nolint:all. For example, if it's used inline (not from the beginning of the line) it excludes issues only for this line.

var bad_name int //nolint:all

To exclude issues from specific linters only:

var bad_name int //nolint:golint,unused

To exclude issues for the block of code use this directive on the beginning of a line:

//nolint:all
func allIssuesInThisFunctionAreExcluded() *string {
  // ...
}

//nolint:govet
var (
  a int
  b int
)

Also, you can exclude all issues in a file by:

//nolint:unparam
package pkg

You may add a comment explaining or justifying why //nolint is being used on the same line as the flag itself:

//nolint:gocyclo // This legacy function is complex but the team too busy to simplify it
func someLegacyFunction() *string {
  // ...
}

You can see more examples of using //nolint in our tests for it.

Use //nolint instead of // nolint because machine-readable comments should have no space by Go convention.

Default Exclusions

Some exclusions are considered as common, to help golangci-lint users those common exclusions are used as default exclusions.

If you don't want to use it you can set issues.exclude-use-default to false. {.DefaultExclusions}