88 lines
2.6 KiB
Go
88 lines
2.6 KiB
Go
package st1019
|
||
|
||
import (
|
||
"fmt"
|
||
"go/ast"
|
||
|
||
"honnef.co/go/tools/analysis/facts/generated"
|
||
"honnef.co/go/tools/analysis/lint"
|
||
"honnef.co/go/tools/analysis/report"
|
||
|
||
"golang.org/x/tools/go/analysis"
|
||
)
|
||
|
||
var SCAnalyzer = lint.InitializeAnalyzer(&lint.Analyzer{
|
||
Analyzer: &analysis.Analyzer{
|
||
Name: "ST1019",
|
||
Run: run,
|
||
Requires: []*analysis.Analyzer{generated.Analyzer},
|
||
},
|
||
Doc: &lint.RawDocumentation{
|
||
Title: `Importing the same package multiple times`,
|
||
Text: `Go allows importing the same package multiple times, as long as
|
||
different import aliases are being used. That is, the following
|
||
bit of code is valid:
|
||
|
||
import (
|
||
"fmt"
|
||
fumpt "fmt"
|
||
format "fmt"
|
||
)
|
||
|
||
However, this is very rarely done on purpose. Usually, it is a
|
||
sign of code that got refactored, accidentally adding duplicate
|
||
import statements. It is also a rarely known feature, which may
|
||
contribute to confusion.
|
||
|
||
Do note that sometimes, this feature may be used
|
||
intentionally (see for example
|
||
https://github.com/golang/go/commit/3409ce39bfd7584523b7a8c150a310cea92d879d)
|
||
– if you want to allow this pattern in your code base, you're
|
||
advised to disable this check.
|
||
|
||
It is acceptable to import the same package twice if one of the imports
|
||
uses the blank identifier. This is allowed in order to increase
|
||
resilience against erroneous changes when using the same package for its
|
||
side effects as well as its exported API.`,
|
||
Since: "2020.1",
|
||
MergeIf: lint.MergeIfAny,
|
||
},
|
||
})
|
||
|
||
var Analyzer = SCAnalyzer.Analyzer
|
||
|
||
func run(pass *analysis.Pass) (any, error) {
|
||
for _, f := range pass.Files {
|
||
// Collect all imports by their import path
|
||
imports := make(map[string][]*ast.ImportSpec, len(f.Imports))
|
||
for _, imp := range f.Imports {
|
||
if imp.Name != nil && imp.Name.Name == "_" {
|
||
// Allow blank imports to coexist with one normal import.
|
||
//
|
||
// We don't have to count the number of blank imports,
|
||
// goimports removes duplicates.
|
||
continue
|
||
}
|
||
imports[imp.Path.Value] = append(imports[imp.Path.Value], imp)
|
||
}
|
||
|
||
for path, value := range imports {
|
||
if path[1:len(path)-1] == "unsafe" {
|
||
// Don't flag unsafe. Cgo generated code imports
|
||
// unsafe as _cgo_unsafe, in addition to the user's import.
|
||
continue
|
||
}
|
||
// If there's more than one import per path, we flag that
|
||
if len(value) > 1 {
|
||
s := fmt.Sprintf("package %s is being imported more than once", path)
|
||
opts := []report.Option{report.FilterGenerated()}
|
||
for _, imp := range value[1:] {
|
||
opts = append(opts, report.Related(imp, fmt.Sprintf("other import of %s", path)))
|
||
}
|
||
report.Report(pass, value[0], s, opts...)
|
||
}
|
||
}
|
||
}
|
||
return nil, nil
|
||
}
|