Merge pull request #14 from gostaticanalysis/add-result

Add result

forcetypeassert.go

@@ -2,6 +2,7 @@ package forcetypeassert
 
 import (
 	"go/ast"
+	"reflect"
 
 	"golang.org/x/tools/go/analysis"
 	"golang.org/x/tools/go/analysis/passes/inspect"
@@ -15,12 +16,35 @@ var Analyzer = &analysis.Analyzer{
 	Requires: []*analysis.Analyzer{
 		inspect.Analyzer,
 	},
+	ResultType: reflect.TypeOf((*Panicable)(nil)),
 }
 
-const Doc = "forcetypeassert is finds type assertions which did forcely such as below."
+// Panicable stores panicable type assertions.
+type Panicable struct {
+	m     map[ast.Node]bool
+	nodes []ast.Node
+}
+
+// Check checks whether the node may occur panic or not.
+func (p *Panicable) Check(n ast.Node) bool {
+	return p.m[n]
+}
+
+// Len is number of panicable nodes.
+func (p *Panicable) Len() int {
+	return len(p.nodes)
+}
+
+// At returns the i-th panicable node.
+func (p *Panicable) At(i int) ast.Node {
+	return p.nodes[i]
+}
+
+const Doc = "forcetypeassert is finds type assertions which did forcely"
 
 func run(pass *analysis.Pass) (interface{}, error) {
-	inspect := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
+	inspect, _ := pass.ResultOf[inspect.Analyzer].(*inspector.Inspector)
+	result := &Panicable{m: make(map[ast.Node]bool)}
 
 	nodeFilter := []ast.Node{
 		(*ast.AssignStmt)(nil),
@@ -34,11 +58,13 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		}
 		switch n := n.(type) {
 		case *ast.AssignStmt:
-			return checkAssignStmt(pass, n)
+			return checkAssignStmt(pass, result, n)
 		case *ast.ValueSpec:
-			return checkValueSpec(pass, n)
+			return checkValueSpec(pass, result, n)
 		case *ast.TypeAssertExpr:
 			if n.Type != nil {
+				result.m[n] = true
+				result.nodes = append(result.nodes, n)
 				pass.Reportf(n.Pos(), "type assertion must be checked")
 			}
 			return false
@@ -47,10 +73,10 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		return true
 	})
 
-	return nil, nil
+	return result, nil
 }
 
-func checkAssignStmt(pass *analysis.Pass, n *ast.AssignStmt) bool {
+func checkAssignStmt(pass *analysis.Pass, result *Panicable, n *ast.AssignStmt) bool {
 	tae := findTypeAssertion(n.Rhs)
 	if tae == nil {
 		return true
@@ -62,6 +88,8 @@ func checkAssignStmt(pass *analysis.Pass, n *ast.AssignStmt) bool {
 		pass.Reportf(n.Pos(), "right hand must be only type assertion")
 		return false
 	case len(n.Lhs) != 2 && tae.Type != nil:
+		result.m[n] = true
+		result.nodes = append(result.nodes, n)
 		pass.Reportf(n.Pos(), "type assertion must be checked")
 		return false
 	case len(n.Lhs) == 2:
@@ -71,7 +99,7 @@ func checkAssignStmt(pass *analysis.Pass, n *ast.AssignStmt) bool {
 	return true
 }
 
-func checkValueSpec(pass *analysis.Pass, n *ast.ValueSpec) bool {
+func checkValueSpec(pass *analysis.Pass, result *Panicable, n *ast.ValueSpec) bool {
 	tae := findTypeAssertion(n.Values)
 	if tae == nil {
 		return true
@@ -83,6 +111,8 @@ func checkValueSpec(pass *analysis.Pass, n *ast.ValueSpec) bool {
 		pass.Reportf(n.Pos(), "right hand must be only type assertion")
 		return false
 	case len(n.Names) != 2 && tae.Type != nil:
+		result.m[n] = true
+		result.nodes = append(result.nodes, n)
 		pass.Reportf(n.Pos(), "type assertion must be checked")
 		return false
 	case len(n.Names) == 2:

forcetypeassert_test.go

@@ -4,10 +4,32 @@ import (
 	"testing"
 
 	"github.com/gostaticanalysis/forcetypeassert"
+	"golang.org/x/tools/go/analysis"
 	"golang.org/x/tools/go/analysis/analysistest"
 )
 
 func Test(t *testing.T) {
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, forcetypeassert.Analyzer, "a")
 }
+
+func TestResult(t *testing.T) {
+	testdata := analysistest.TestData()
+	a := &analysis.Analyzer{
+		Name: "test",
+		Doc:  "test",
+		Requires: []*analysis.Analyzer{
+			forcetypeassert.Analyzer,
+		},
+		Run: func(pass *analysis.Pass) (interface{}, error) {
+			panicable, _ := pass.ResultOf[forcetypeassert.Analyzer].(*forcetypeassert.Panicable)
+			for i := 0; i < panicable.Len(); i++ {
+				n := panicable.At(i)
+				pass.Reportf(n.Pos(), "panicable")
+			}
+			return nil, nil
+		},
+	}
+
+	analysistest.Run(t, testdata, a, "b")
+}

testdata/src/b/b.go

@@ -0,0 +1,47 @@
+package b
+
+import "fmt"
+
+var _, _ = ((interface{})(nil)).(string)       // OK
+var _ = ((interface{})(nil)).(string)          // want `panicable`
+var _, _ = ((interface{})(nil)).(string), true // OK
+
+func f() {
+	var i interface{} = "hello"
+
+	_ = i.(string) // want `panicable`
+
+	_, _ = i.(string), "foo" // OK
+
+	s, ok := i.(string) // ok
+	s, _ = i.(string)   // ok
+	fmt.Println(s, ok)
+
+	if s, ok := i.(string); ok { // ok
+		println(s)
+	}
+
+	switch n := i.(type) { // ok
+	case string:
+		fmt.Println(n)
+	}
+	switch i.(type) { // ok
+	case string:
+	}
+
+	var _ = i.(string) // want `panicable`
+
+	var _ = *i.(*string) // want `panicable`
+
+	println(i.(string))   // want `panicable`
+	println(*i.(*string)) // want `panicable`
+
+	_ = func() int {
+		println(*i.(*string)) // want `panicable`
+		return 0
+	}()
+
+	func() {
+		println(*i.(*string)) // want `panicable`
+	}()
+}