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|
package analyzer
import (
"flag"
"go/ast"
"go/token"
"strings"
"golang.org/x/tools/go/analysis"
)
//nolint:gochecknoglobals
var flagSet flag.FlagSet
//nolint:gochecknoglobals
var (
maxComplexity int
packageAverage float64
skipTests bool
)
const (
defaultMaxComplexity = 10
)
//nolint:gochecknoinits
func init() {
flagSet.IntVar(&maxComplexity, "maxComplexity", defaultMaxComplexity, "max complexity the function can have")
flagSet.Float64Var(&packageAverage, "packageAverage", 0, "max average complexity in package")
flagSet.BoolVar(&skipTests, "skipTests", false, "should the linter execute on test files as well")
}
func NewAnalyzer() *analysis.Analyzer {
return &analysis.Analyzer{
Name: "cyclop",
Doc: "checks function and package cyclomatic complexity",
Run: run,
Flags: flagSet,
}
}
func run(pass *analysis.Pass) (interface{}, error) {
var sum, count float64
var pkgName string
var pkgPos token.Pos
for _, file := range pass.Files {
ast.Inspect(file, func(node ast.Node) bool {
funcDecl, ok := node.(*ast.FuncDecl)
if !ok {
if node == nil {
return true
}
if file, ok := node.(*ast.File); ok {
pkgName = file.Name.Name
pkgPos = node.Pos()
}
// we check function by function
return true
}
if skipTests && testFunc(funcDecl) {
return true
}
count++
comp := complexity(funcDecl)
sum += float64(comp)
if comp > maxComplexity {
pass.Reportf(node.Pos(), "calculated cyclomatic complexity for function %s is %d, max is %d", funcDecl.Name.Name, comp, maxComplexity)
}
return true
})
}
if packageAverage > 0 {
avg := sum / count
if avg > packageAverage {
pass.Reportf(pkgPos, "the average complexity for the package %s is %f, max is %f", pkgName, avg, packageAverage)
}
}
return nil, nil
}
func testFunc(f *ast.FuncDecl) bool {
return strings.HasPrefix(f.Name.Name, "Test")
}
func complexity(fn *ast.FuncDecl) int {
v := complexityVisitor{}
ast.Walk(&v, fn)
return v.Complexity
}
type complexityVisitor struct {
Complexity int
}
func (v *complexityVisitor) Visit(n ast.Node) ast.Visitor {
switch n := n.(type) {
case *ast.FuncDecl, *ast.IfStmt, *ast.ForStmt, *ast.RangeStmt, *ast.CaseClause, *ast.CommClause:
v.Complexity++
case *ast.BinaryExpr:
if n.Op == token.LAND || n.Op == token.LOR {
v.Complexity++
}
}
return v
}
|
