Merge pull request #22 from zimmski/noop-all-the-way

Noop all the way
zimmski · Jun 23, 2016 · fdfaaf4 · fdfaaf4
2 parents 54a00d2 + 1a3ed25
commit fdfaaf4
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Showing 14 changed files with 92 additions and 59 deletions.
diff --git a/astutil/create.go b/astutil/create.go
@@ -0,0 +1,36 @@
+package astutil
+
+import (
+	"go/ast"
+	"go/token"
+)
+
+// CreateNoopOfStatement creates a syntactically safe noop statement out of a given statement.
+func CreateNoopOfStatement(stmt ast.Stmt) ast.Stmt {
+	return CreateNoopOfStatements([]ast.Stmt{stmt})
+}
+
+// CreateNoopOfStatement creates a syntactically safe noop statement out of a given statement.
+func CreateNoopOfStatements(stmts []ast.Stmt) ast.Stmt {
+	var ids []ast.Expr
+	for _, stmt := range stmts {
+		ids = append(ids, IdentifiersInStatement(stmt)...)
+	}
+
+	if len(ids) == 0 {
+		return &ast.EmptyStmt{
+			Semicolon: token.NoPos,
+		}
+	}
+
+	lhs := make([]ast.Expr, len(ids))
+	for i := range ids {
+		lhs[i] = ast.NewIdent("_")
+	}
+
+	return &ast.AssignStmt{
+		Lhs: lhs,
+		Rhs: ids,
+		Tok: token.ASSIGN,
+	}
+}
diff --git a/astutil/query.go b/astutil/query.go
@@ -0,0 +1,33 @@
+package astutil
+
+import (
+	"go/ast"
+)
+
+// IdentifiersInStatement returns all identifiers with their found in a statement.
+func IdentifiersInStatement(stmt ast.Stmt) []ast.Expr {
+	w := &identifierWalker{}
+
+	ast.Walk(w, stmt)
+
+	return w.identifiers
+}
+
+type identifierWalker struct {
+	identifiers []ast.Expr
+}
+
+func (w *identifierWalker) Visit(node ast.Node) ast.Visitor {
+	switch n := node.(type) {
+	case *ast.Ident:
+		w.identifiers = append(w.identifiers, n)
+
+		return nil
+	case *ast.SelectorExpr:
+		w.identifiers = append(w.identifiers, n)
+
+		return nil
+	}
+
+	return w
+}
diff --git a/cmd/go-mutesting/main_test.go b/cmd/go-mutesting/main_test.go
@@ -44,5 +44,5 @@ func TestMain(t *testing.T) {
 	out := <-bufChannel
 
 	assert.Equal(t, returnOk, exitCode)
-	assert.Contains(t, out, "The mutation score is 0.578947 (11 passed, 8 failed, 2 skipped, total is 21)")
+	assert.Contains(t, out, "The mutation score is 0.583333 (7 passed, 5 failed, 1 skipped, total is 13)")
 }
diff --git a/mutator/branch/mutatecase.go b/mutator/branch/mutatecase.go
@@ -3,6 +3,7 @@ package branch
 import (
 	"go/ast"
 
+	"github.com/zimmski/go-mutesting/astutil"
 	"github.com/zimmski/go-mutesting/mutator"
 )
 
@@ -47,7 +48,9 @@ func (m *MutatorCase) Mutate(node ast.Node, changed chan bool) {
 	}
 
 	old := n.Body
-	n.Body = make([]ast.Stmt, 0)
+	n.Body = []ast.Stmt{
+		astutil.CreateNoopOfStatements(n.Body),
+	}
 
 	changed <- true
 	<-changed

diff --git a/mutator/branch/mutateelse.go b/mutator/branch/mutateelse.go
@@ -3,6 +3,7 @@ package branch
 import (
 	"go/ast"
 
+	"github.com/zimmski/go-mutesting/astutil"
 	"github.com/zimmski/go-mutesting/mutator"
 )
 
@@ -56,9 +57,7 @@ func (m *MutatorElse) Mutate(node ast.Node, changed chan bool) {
 	}
 
 	old := n.Else
-	n.Else = &ast.EmptyStmt{
-		Semicolon: n.Else.Pos(),
-	}
+	n.Else = astutil.CreateNoopOfStatement(old)
 
 	changed <- true
 	<-changed

diff --git a/mutator/branch/mutateif.go b/mutator/branch/mutateif.go
@@ -3,6 +3,7 @@ package branch
 import (
 	"go/ast"
 
+	"github.com/zimmski/go-mutesting/astutil"
 	"github.com/zimmski/go-mutesting/mutator"
 )
 
@@ -47,7 +48,9 @@ func (m *MutatorIf) Mutate(node ast.Node, changed chan bool) {
 	}
 
 	old := n.Body.List
-	n.Body.List = make([]ast.Stmt, 0)
+	n.Body.List = []ast.Stmt{
+		astutil.CreateNoopOfStatement(n.Body),
+	}
 
 	changed <- true
 	<-changed

diff --git a/mutator/statement/remove.go b/mutator/statement/remove.go
@@ -4,6 +4,7 @@ import (
 	"go/ast"
 	"go/token"
 
+	"github.com/zimmski/go-mutesting/astutil"
 	"github.com/zimmski/go-mutesting/mutator"
 )
 
@@ -85,7 +86,7 @@ func (m *MutatorRemoveStatement) Mutate(node ast.Node, changed chan bool) {
 	for i, ni := range l {
 		if m.checkStatement(ni) {
 			old := l[i]
-			l[i] = createNoop(old)
+			l[i] = astutil.CreateNoopOfStatement(old)
 
 			changed <- true
 			<-changed
@@ -98,48 +99,6 @@ func (m *MutatorRemoveStatement) Mutate(node ast.Node, changed chan bool) {
 	}
 }
 
-func createNoop(old ast.Stmt) ast.Stmt {
-	v := &idCollector{}
-	ast.Walk(v, old)
-	return v.generateStatement(old)
-}
-
-type idCollector struct {
-	Ids []ast.Expr
-}
-
-func (i *idCollector) Visit(node ast.Node) ast.Visitor {
-	switch v := node.(type) {
-	case *ast.Ident:
-		i.Ids = append(i.Ids, v)
-		return nil
-	case *ast.SelectorExpr:
-		i.Ids = append(i.Ids, v)
-		return nil
-	}
-	return i
-}
-
-func (i *idCollector) generateStatement(old ast.Stmt) ast.Stmt {
-	if len(i.Ids) == 0 {
-		return &ast.EmptyStmt{
-			Semicolon: old.Pos(),
-		}
-	}
-
-	lhs := make([]ast.Expr, len(i.Ids))
-	for i := range i.Ids {
-		lhs[i] = ast.NewIdent("_")
-	}
-
-	return &ast.AssignStmt{
-		Lhs:    lhs,
-		Rhs:    i.Ids,
-		Tok:    token.ASSIGN,
-		TokPos: old.Pos(),
-	}
-}
-
 // String implements the String method of the Stringer interface
 func (m MutatorRemoveStatement) String() string {
 	return "statement/remove"

diff --git a/scripts/lint.sh b/scripts/lint.sh
@@ -5,18 +5,18 @@ if [ -z ${ROOT_DIR+x} ]; then echo "ROOT_DIR is not set"; exit 1; fi
 
 echo "gofmt:"
 OUT=$(gofmt -l $ROOT_DIR)
-if [ $($OUT | wc -l) -ne 0 ]; then echo $OUT; PROBLEM=1; fi
+if [ $(echo -n "$OUT" | wc -l) -ne 0 ]; then echo -n "$OUT"; PROBLEM=1; fi
 
 echo "errcheck:"
 OUT=$(errcheck $PKG/...)
-if [ $($OUT | wc -l) -ne 0 ]; then echo $OUT; PROBLEM=1; fi
+if [ $(echo -n "$OUT" | wc -l) -ne 0 ]; then echo -n "$OUT"; PROBLEM=1; fi
 
 echo "go vet:"
 OUT=$(go tool vet -all=true -v=true $ROOT_DIR 2>&1 | grep --invert-match -P "(Checking file|\%p of wrong type|can't check non-constant format|not compatible with reflect.StructTag.Get)")
-if [ $($OUT | wc -l) -ne 0 ]; then echo $OUT; PROBLEM=1; fi
+if [ $(echo -n "$OUT" | wc -l) -ne 0 ]; then echo -n "$OUT"; PROBLEM=1; fi
 
 echo "golint:"
 OUT=$(golint $PKG/... | grep --invert-match -P "(_string.go:)")
-if [ $($OUT | wc -l) -ne 0 ]; then echo $OUT; PROBLEM=1; fi
+if [ $(echo -n "$OUT" | wc -l) -ne 0 ]; then echo -n "$OUT"; PROBLEM=1; fi
 
 if [ -n "$PROBLEM" ]; then exit 1; fi
diff --git a/testdata/branch/mutatecase.go.0.go b/testdata/branch/mutatecase.go.0.go
@@ -12,7 +12,7 @@ func main() {
 	for i != 4 {
 		switch {
 		case i == 1:
-
+			_, _ = fmt.Println, i
 		case i == 2:
 			fmt.Println(i * 2)
 		default:

diff --git a/testdata/branch/mutatecase.go.1.go b/testdata/branch/mutatecase.go.1.go
@@ -14,7 +14,7 @@ func main() {
 		case i == 1:
 			fmt.Println(i)
 		case i == 2:
-
+			_, _ = fmt.Println, i
 		default:
 			fmt.Println(i * 3)
 		}

diff --git a/testdata/branch/mutatecase.go.2.go b/testdata/branch/mutatecase.go.2.go
@@ -16,7 +16,7 @@ func main() {
 		case i == 2:
 			fmt.Println(i * 2)
 		default:
-
+			_, _ = fmt.Println, i
 		}
 
 		i++

diff --git a/testdata/branch/mutateelse.go.0.go b/testdata/branch/mutateelse.go.0.go
@@ -15,7 +15,7 @@ func main() {
 		} else if i == 2 {
 			fmt.Println(i * 2)
 		} else {
-
+			_, _ = fmt.Println, i
 		}
 
 		i++

diff --git a/testdata/branch/mutateif.go.0.go b/testdata/branch/mutateif.go.0.go
@@ -11,7 +11,7 @@ func main() {
 
 	for i != 4 {
 		if i == 1 {
-
+			_, _ = fmt.Println, i
 		} else if i == 2 {
 			fmt.Println(i * 2)
 		} else {

diff --git a/testdata/branch/mutateif.go.1.go b/testdata/branch/mutateif.go.1.go
@@ -13,7 +13,7 @@ func main() {
 		if i == 1 {
 			fmt.Println(i)
 		} else if i == 2 {
-
+			_, _ = fmt.Println, i
 		} else {
 			fmt.Println(i * 3)
 		}