Merge pull request #15 from drystone/loop-vars

pkg/paralleltest/paralleltest.go

@@ -2,6 +2,7 @@ package paralleltest
 
 import (
 	"go/ast"
+	"go/types"
 	"strings"
 
 	"golang.org/x/tools/go/analysis"
@@ -34,9 +35,8 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		funcDecl := node.(*ast.FuncDecl)
 		var funcHasParallelMethod,
 			rangeStatementOverTestCasesExists,
-			rangeStatementHasParallelMethod,
-			testLoopVariableReinitialised bool
-		var testRunLoopIdentifier string
+			rangeStatementHasParallelMethod bool
+		var loopVariableUsedInRun *string
 		var numberOfTestRun int
 		var positionOfTestRunNode []ast.Node
 		var rangeNode ast.Node
@@ -81,6 +81,13 @@ func run(pass *analysis.Pass) (interface{}, error) {
 			case *ast.RangeStmt:
 				rangeNode = v
 
+				var loopVars []types.Object
+				for _, expr := range []ast.Expr{v.Key, v.Value} {
+					if id, ok := expr.(*ast.Ident); ok {
+						loopVars = append(loopVars, pass.TypesInfo.ObjectOf(id))
+					}
+				}
+
 				ast.Inspect(v, func(n ast.Node) bool {
 					// nolint: gocritic
 					switch r := n.(type) {
@@ -90,26 +97,20 @@ func run(pass *analysis.Pass) (interface{}, error) {
 							innerTestVar := getRunCallbackParameterName(r.X)
 
 							rangeStatementOverTestCasesExists = true
-							testRunLoopIdentifier = methodRunFirstArgumentObjectName(r.X)
 
 							if !rangeStatementHasParallelMethod {
 								rangeStatementHasParallelMethod = methodParallelIsCalledInMethodRun(r.X, innerTestVar)
 							}
+
+							if loopVariableUsedInRun == nil {
+								if run, ok := r.X.(*ast.CallExpr); ok {
+									loopVariableUsedInRun = loopVarReferencedInRun(run, loopVars, pass.TypesInfo)
+								}
+							}
 						}
 					}
 					return true
 				})
-
-				// Check for the range loop value identifier re assignment
-				// More info here https://gist.github.com/kunwardeep/80c2e9f3d3256c894898bae82d9f75d0
-				if rangeStatementOverTestCasesExists {
-					var rangeValueIdentifier string
-					if i, ok := v.Value.(*ast.Ident); ok {
-						rangeValueIdentifier = i.Name
-					}
-
-					testLoopVariableReinitialised = testCaseLoopVariableReinitialised(v.Body.List, rangeValueIdentifier, testRunLoopIdentifier)
-				}
 			}
 		}
 
@@ -120,12 +121,8 @@ func run(pass *analysis.Pass) (interface{}, error) {
 		if rangeStatementOverTestCasesExists && rangeNode != nil {
 			if !rangeStatementHasParallelMethod {
 				pass.Reportf(rangeNode.Pos(), "Range statement for test %s missing the call to method parallel in test Run\n", funcDecl.Name.Name)
-			} else {
-				if testRunLoopIdentifier == "" {
-					pass.Reportf(rangeNode.Pos(), "Range statement for test %s does not use range value in test Run\n", funcDecl.Name.Name)
-				} else if !testLoopVariableReinitialised {
-					pass.Reportf(rangeNode.Pos(), "Range statement for test %s does not reinitialise the variable %s\n", funcDecl.Name.Name, testRunLoopIdentifier)
-				}
+			} else if loopVariableUsedInRun != nil {
+				pass.Reportf(rangeNode.Pos(), "Range statement for test %s does not reinitialise the variable %s\n", funcDecl.Name.Name, *loopVariableUsedInRun)
 			}
 		}
 
@@ -140,38 +137,6 @@ func run(pass *analysis.Pass) (interface{}, error) {
 	return nil, nil
 }
 
-func testCaseLoopVariableReinitialised(statements []ast.Stmt, rangeValueIdentifier string, testRunLoopIdentifier string) bool {
-	if len(statements) > 1 {
-		for _, s := range statements {
-			leftIdentifier, rightIdentifier := getLeftAndRightIdentifier(s)
-			if leftIdentifier == testRunLoopIdentifier && rightIdentifier == rangeValueIdentifier {
-				return true
-			}
-		}
-	}
-	return false
-}
-
-// Return the left hand side and the right hand side identifiers name
-func getLeftAndRightIdentifier(s ast.Stmt) (string, string) {
-	var leftIdentifier, rightIdentifier string
-	// nolint: gocritic
-	switch v := s.(type) {
-	case *ast.AssignStmt:
-		if len(v.Rhs) == 1 {
-			if i, ok := v.Rhs[0].(*ast.Ident); ok {
-				rightIdentifier = i.Name
-			}
-		}
-		if len(v.Lhs) == 1 {
-			if i, ok := v.Lhs[0].(*ast.Ident); ok {
-				leftIdentifier = i.Name
-			}
-		}
-	}
-	return leftIdentifier, rightIdentifier
-}
-
 func methodParallelIsCalledInMethodRun(node ast.Node, testVar string) bool {
 	var methodParallelCalled bool
 	// nolint: gocritic
@@ -247,22 +212,6 @@ func getRunCallbackParameterName(node ast.Node) string {
 	return ""
 }
 
-// Gets the object name `tc` from method t.Run(tc.Foo, func(t *testing.T)
-func methodRunFirstArgumentObjectName(node ast.Node) string {
-	// nolint: gocritic
-	switch n := node.(type) {
-	case *ast.CallExpr:
-		for _, arg := range n.Args {
-			if s, ok := arg.(*ast.SelectorExpr); ok {
-				if i, ok := s.X.(*ast.Ident); ok {
-					return i.Name
-				}
-			}
-		}
-	}
-	return ""
-}
-
 // Checks if the function has the param type *testing.T; if it does, then the
 // parameter name is returned, too.
 func isTestFunction(funcDecl *ast.FuncDecl) (bool, string) {
@@ -291,3 +240,24 @@ func isTestFunction(funcDecl *ast.FuncDecl) (bool, string) {
 
 	return false, ""
 }
+
+func loopVarReferencedInRun(call *ast.CallExpr, vars []types.Object, typeInfo *types.Info) (found *string) {
+	if len(call.Args) != 2 {
+		return
+	}
+
+	ast.Inspect(call.Args[1], func(n ast.Node) bool {
+		ident, ok := n.(*ast.Ident)
+		if !ok {
+			return true
+		}
+		for _, o := range vars {
+			if typeInfo.ObjectOf(ident) == o {
+				found = &ident.Name
+			}
+		}
+		return true
+	})
+
+	return
+}

pkg/paralleltest/testdata/src/t/t_test.go

@@ -81,7 +81,7 @@ func TestFunctionRangeNotUsingRangeValueInTDotRun(t *testing.T) {
 	testCases := []struct {
 		name string
 	}{{name: "foo"}}
-	for _, tc := range testCases { // want "Range statement for test TestFunctionRangeNotUsingRangeValueInTDotRun does not use range value in test Run"
+	for _, tc := range testCases { // want "Range statement for test TestFunctionRangeNotUsingRangeValueInTDotRun does not reinitialise the variable tc"
 		t.Run("tc.name", func(t *testing.T) {
 			t.Parallel()
 			fmt.Println(tc.name)