dnscrypt-proxy/vendor/github.com/fzipp/gocyclo/complexity.go

49 lines
1.1 KiB
Go

// Copyright 2020 Frederik Zipp. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package gocyclo calculates the cyclomatic complexities of functions and
// methods in Go source code.
package gocyclo
import (
"go/ast"
"go/token"
)
// Complexity calculates the cyclomatic complexity of a function.
// The 'fn' node is either a *ast.FuncDecl or a *ast.FuncLit.
func Complexity(fn ast.Node) int {
v := complexityVisitor{
complexity: 1,
}
ast.Walk(&v, fn)
return v.complexity
}
type complexityVisitor struct {
// complexity is the cyclomatic complexity
complexity int
}
// Visit implements the ast.Visitor interface.
func (v *complexityVisitor) Visit(n ast.Node) ast.Visitor {
switch n := n.(type) {
case *ast.IfStmt, *ast.ForStmt, *ast.RangeStmt:
v.complexity++
case *ast.CaseClause:
if n.List != nil { // ignore default case
v.complexity++
}
case *ast.CommClause:
if n.Comm != nil { // ignore default case
v.complexity++
}
case *ast.BinaryExpr:
if n.Op == token.LAND || n.Op == token.LOR {
v.complexity++
}
}
return v
}