1 files changed, 115 insertions, 0 deletions
diff --git a/vendor/github.com/mgechev/revive/rule/cyclomatic.go b/vendor/github.com/mgechev/revive/rule/cyclomatic.go
new file mode 100644
index 0000000000..48ea80a6aa
--- /dev/null
+++ b/vendor/github.com/mgechev/revive/rule/cyclomatic.go
@@ -0,0 +1,115 @@
+package rule
+
+import (
+	"fmt"
+	"go/ast"
+	"go/token"
+
+	"github.com/mgechev/revive/lint"
+)
+
+// Based on https://github.com/fzipp/gocyclo
+
+// CyclomaticRule lints given else constructs.
+type CyclomaticRule struct{}
+
+// Apply applies the rule to given file.
+func (r *CyclomaticRule) Apply(file *lint.File, arguments lint.Arguments) []lint.Failure {
+	var failures []lint.Failure
+
+	complexity, ok := arguments[0].(int64) // Alt. non panicking version
+	if !ok {
+		panic("invalid argument for cyclomatic complexity")
+	}
+
+	fileAst := file.AST
+	walker := lintCyclomatic{
+		file:       file,
+		complexity: int(complexity),
+		onFailure: func(failure lint.Failure) {
+			failures = append(failures, failure)
+		},
+	}
+
+	ast.Walk(walker, fileAst)
+
+	return failures
+}
+
+// Name returns the rule name.
+func (r *CyclomaticRule) Name() string {
+	return "cyclomatic"
+}
+
+type lintCyclomatic struct {
+	file       *lint.File
+	complexity int
+	onFailure  func(lint.Failure)
+}
+
+func (w lintCyclomatic) Visit(_ ast.Node) ast.Visitor {
+	f := w.file
+	for _, decl := range f.AST.Decls {
+		if fn, ok := decl.(*ast.FuncDecl); ok {
+			c := complexity(fn)
+			if c > w.complexity {
+				w.onFailure(lint.Failure{
+					Confidence: 1,
+					Category:   "maintenance",
+					Failure:    fmt.Sprintf("function %s has cyclomatic complexity %d", funcName(fn), c),
+					Node:       fn,
+				})
+			}
+		}
+	}
+	return nil
+}
+
+// funcName returns the name representation of a function or method:
+// "(Type).Name" for methods or simply "Name" for functions.
+func funcName(fn *ast.FuncDecl) string {
+	if fn.Recv != nil {
+		if fn.Recv.NumFields() > 0 {
+			typ := fn.Recv.List[0].Type
+			return fmt.Sprintf("(%s).%s", recvString(typ), fn.Name)
+		}
+	}
+	return fn.Name.Name
+}
+
+// recvString returns a string representation of recv of the
+// form "T", "*T", or "BADRECV" (if not a proper receiver type).
+func recvString(recv ast.Expr) string {
+	switch t := recv.(type) {
+	case *ast.Ident:
+		return t.Name
+	case *ast.StarExpr:
+		return "*" + recvString(t.X)
+	}
+	return "BADRECV"
+}
+
+// complexity calculates the cyclomatic complexity of a function.
+func complexity(fn *ast.FuncDecl) int {
+	v := complexityVisitor{}
+	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.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
+}