Enable directive for the Analyzer (#33)

README.md

@@ -1,6 +1,6 @@
 [![GoDoc](https://godoc.org/github.com/uudashr/gocognit?status.svg)](https://godoc.org/github.com/uudashr/gocognit)
 # Gocognit
-Gocognit calculates cognitive complexities of functions in Go source code. A measurement of how hard does the code is intuitively to understand.
+Gocognit calculates cognitive complexities of functions (and methods) in Go source code. A measurement of how hard does the code is intuitively to understand.
 
 ## Understanding the complexity
 
@@ -207,6 +207,15 @@ The output fields for each line are:
 <complexity> <package> <function> <file:row:column>
 ```
 
+## Ignore individual functions
+Ignore individual functions by specifying `gocognit:ignore` directive.
+```go
+//gocognit:ignore
+func IgnoreMe() {
+    // ...
+}
+```
+
 ## Related project
 - [Gocyclo](https://github.com/fzipp/gocyclo) where the code are based on.
 - [Cognitive Complexity: A new way of measuring understandability](https://www.sonarsource.com/docs/CognitiveComplexity.pdf) white paper by G. Ann Campbell.

gocognit.go

@@ -379,13 +379,19 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		(*ast.FuncDecl)(nil),
 	}
 	inspect.Preorder(nodeFilter, func(n ast.Node) {
-		fnDecl := n.(*ast.FuncDecl)
+		funcDecl := n.(*ast.FuncDecl)
 
-		fnName := funcName(fnDecl)
-		fnComplexity := Complexity(fnDecl)
+		d := parseDirective(funcDecl.Doc)
+		if d.Ignore {
+			return
+		}
+
+		fnName := funcName(funcDecl)
+
+		fnComplexity := Complexity(funcDecl)
 
 		if fnComplexity > over {
-			pass.Reportf(fnDecl.Pos(), "cognitive complexity %d of func %s is high (> %d)", fnComplexity, fnName, over)
+			pass.Reportf(funcDecl.Pos(), "cognitive complexity %d of func %s is high (> %d)", fnComplexity, fnName, over)
 		}
 	})
 

testdata/src/a/a.go

@@ -238,3 +238,12 @@ func MyFunc2(a bool) { // want "cognitive complexity 2 of func MyFunc2 is high \
 
 	x()
 } // total complexity = 2
+
+//gocognit:ignore
+func IgnoreMe(name string) bool {
+	if name == "me" { // +1
+		return true
+	}
+
+	return false
+} // total complexity = 1

testdata/src/b/b.go

@@ -230,3 +230,12 @@ func MyFunc2(a bool) {
 
 	x()
 } // total complexity = 2
+
+//gocognit:ignore
+func IgnoreMe(name string) bool {
+	if name == "me" { // +1
+		return true
+	}
+
+	return false
+} // total complexity = 1