Dispatcher to handle anon func returned in closure (#27)

Author: dfava

querysql/gomssqldispatcher.go

@@ -4,16 +4,18 @@ import (
 	"database/sql"
 	"fmt"
 	"reflect"
+	"regexp"
 	"runtime"
 	"strconv"
 	"strings"
 )
 
 type funcInfo struct {
-	name    string
-	numArgs int
-	argType []reflect.Type
-	valueOf reflect.Value
+	name      string
+	numArgs   int
+	isClosure bool
+	argType   []reflect.Type
+	valueOf   reflect.Value
 }
 
 func GoMSSQLDispatcher(fs []interface{}) RowsGoDispatcher {
@@ -30,13 +32,21 @@ func GoMSSQLDispatcher(fs []interface{}) RowsGoDispatcher {
 		}
 
 		fInfo.valueOf = reflect.ValueOf(f)
-		getFunctionName := func(fullName string) string {
+		getFunctionName := func(fullName string) (string, bool) {
 			paths := strings.Split(fullName, "/")
 			lastPath := paths[len(paths)-1]
 			parts := strings.Split(lastPath, ".")
-			return parts[len(parts)-1]
+			fName := parts[len(parts)-1]
+			matched, err := regexp.Match(`func\d+`, []byte(fName))
+			if err != nil {
+				panic(err.Error())
+			}
+			if matched {
+				return parts[len(parts)-2], true // It is a closure
+			}
+			return fName, false
 		}
-		fInfo.name = getFunctionName(runtime.FuncForPC(fInfo.valueOf.Pointer()).Name())
+		fInfo.name, fInfo.isClosure = getFunctionName(runtime.FuncForPC(fInfo.valueOf.Pointer()).Name())
 
 		if knownFuncs == "" {
 			knownFuncs = fmt.Sprintf("'%s'", fInfo.name)
@@ -51,6 +61,9 @@ func GoMSSQLDispatcher(fs []interface{}) RowsGoDispatcher {
 		for i := 0; i < fInfo.numArgs; i++ {
 			fInfo.argType[i] = funcType.In(i)
 		}
+		if _, in := funcMap[fInfo.name]; in {
+			panic(fmt.Sprintf("Function already in dispatcher %s (closure==%v)", fInfo.name, fInfo.isClosure))
+		}
 		funcMap[fInfo.name] = fInfo
 	}
 

querysql/querysql_test.go

@@ -714,3 +714,64 @@ values (42.00);
 	assert.NoError(t, err)
 	assert.Equal(t, "42.00", m.String())
 }
+
+func TestAnonDispatcherFunc(t *testing.T) {
+	qry := `
+if OBJECT_ID('dbo.MyUsers', 'U') is not null drop table MyUsers
+create table MyUsers (
+    ID INT IDENTITY(1,1) PRIMARY KEY,
+    Username NVARCHAR(50)
+);
+insert into MyUsers (Username) values ('JohnDoe');
+
+-- logging
+select _log='info', Y = 'one';
+
+-- dispatcher
+select _function='TestFunction', component = 'abc', val=1, time=1.23;
+
+select _function='ReturnAnonFunc', label = 'myLabel', time=1.23;
+`
+
+	var hook LogHook
+	logger := logrus.StandardLogger()
+	logger.Hooks.Add(&hook)
+	ctx := querysql.WithLogger(context.Background(), querysql.LogrusMSSQLLogger(logger, logrus.InfoLevel))
+	ctx = querysql.WithDispatcher(ctx, querysql.GoMSSQLDispatcher([]interface{}{
+		testhelper.TestFunction,
+		testhelper.ReturnAnonFunc("myComponent"),
+	}))
+	testhelper.ResetTestFunctionsCalled()
+
+	_, err := querysql.ExecContext(ctx, sqldb, qry, "world")
+	assert.NoError(t, err)
+
+	assert.True(t, testhelper.TestFunctionsCalled["ReturnAnonFunc.myComponent"])
+
+	// Check that we have exhausted the logging select before we do the call that gets ErrNoMoreSets
+	assert.Equal(t, []logrus.Fields{
+		{"Y": "one"},
+	}, hook.lines)
+
+	assert.True(t, testhelper.TestFunctionsCalled["TestFunction"])
+}
+
+func TestDispatcherPanicsWithTwoAnonFuncs(t *testing.T) {
+	var mustNotBeTrue bool
+	var hook LogHook
+	logger := logrus.StandardLogger()
+	logger.Hooks.Add(&hook)
+	defer func() {
+		r := recover()
+		assert.NotNil(t, r) // nil if a panic didn't happen, not nil if a panic happened
+		assert.False(t, mustNotBeTrue)
+	}()
+
+	ctx := querysql.WithLogger(context.Background(), querysql.LogrusMSSQLLogger(logger, logrus.InfoLevel))
+	ctx = querysql.WithDispatcher(ctx, querysql.GoMSSQLDispatcher([]interface{}{
+		testhelper.ReturnAnonFunc("myComponent"),
+		testhelper.ReturnAnonFunc("myComponent2"), // This should cause a panic
+	}))
+	// Nothing here gets executed because we expect the WithDispatcher to have panicked
+	mustNotBeTrue = true
+}

querysql/testhelper/helper.go

@@ -23,6 +23,12 @@ func OtherTestFunction(time float64, money float64) {
 	TestFunctionsCalled[getFunctionName()] = true
 }
 
+func ReturnAnonFunc(component string) func(string, float64) {
+	return func(label string, time float64) {
+		TestFunctionsCalled[fmt.Sprintf("ReturnAnonFunc.%s", component)] = true
+	}
+}
+
 func ResetTestFunctionsCalled() {
 	for k, _ := range TestFunctionsCalled {
 		TestFunctionsCalled[k] = false