Added attempt to show rule name when Rule entry fails (#408)

Co-authored-by: Ferdinand Neman <[email protected]>

ast/ArgumentList.go

@@ -134,6 +134,7 @@ func (e *ArgumentList) Evaluate(dataContext IDataContext, memory *WorkingMemory)
 	for i, exp := range e.Arguments {
 		val, err := exp.Evaluate(dataContext, memory)
 		if err != nil {
+
 			return values, err
 		}
 		values[i] = val

ast/ArrayMapSelector.go

@@ -128,6 +128,7 @@ func (e *ArrayMapSelector) Evaluate(dataContext IDataContext, memory *WorkingMem
 	if e.Expression != nil {
 		val, err := e.Expression.Evaluate(dataContext, memory)
 		if err != nil {
+
 			return val, err
 		}
 		e.Value = val

ast/DataContext.go

@@ -39,6 +39,7 @@ type DataContext struct {
 	retracted           []string
 	variableChangeCount uint64
 	complete            bool
+	ruleEntry           *RuleEntry
 }
 
 func (ctx *DataContext) GetKeys() []string {
@@ -63,6 +64,15 @@ func (ctx *DataContext) IsComplete() bool {
 	return ctx.complete
 }
 
+func (ctx *DataContext) GetRuleEntry() *RuleEntry {
+
+	return ctx.ruleEntry
+}
+
+func (ctx *DataContext) SetRuleEntry(re *RuleEntry) {
+	ctx.ruleEntry = re
+}
+
 // IDataContext is the interface for the DataContext struct.
 type IDataContext interface {
 	ResetVariableChangeCount()
@@ -80,6 +90,9 @@ type IDataContext interface {
 	IsComplete() bool
 	Retracted() []string
 	Reset()
+
+	SetRuleEntry(re *RuleEntry)
+	GetRuleEntry() *RuleEntry
 }
 
 // ResetVariableChangeCount will reset the variable change count

ast/RuleEntry.go

@@ -167,7 +167,7 @@ func (e *RuleEntry) SetGrlText(grlText string) {
 func (e *RuleEntry) Evaluate(ctx context.Context, dataContext IDataContext, memory *WorkingMemory) (can bool, err error) {
 	if ctx.Err() != nil {
 
-		return false, ctx.Err()
+		return false, fmt.Errorf("context error on evaluating rule %s. got %w", e.RuleName, ctx.Err())
 	}
 	defer func() {
 		if r := recover(); r != nil {
@@ -176,17 +176,18 @@ func (e *RuleEntry) Evaluate(ctx context.Context, dataContext IDataContext, memo
 		}
 	}()
 	if e.Retracted {
+
 		return false, nil
 	}
 	val, err := e.WhenScope.Evaluate(dataContext, memory)
 	if err != nil {
 		AstLog.Errorf("Error while evaluating rule %s, got %v", e.RuleName, err)
 
-		return false, err
+		return false, fmt.Errorf("evaluating expression in rule '%s' the when raised an error. got %v", dataContext.GetRuleEntry().RuleName, err)
 	}
 	if val.Kind() != reflect.Bool {
 
-		return false, fmt.Errorf("expression in when is not a boolean expression : %s", e.WhenScope.Expression.GetGrlText())
+		return false, fmt.Errorf("evaluating expression in rule '%s', the when is not a boolean expression : %s", dataContext.GetRuleEntry().RuleName, e.WhenScope.Expression.GetGrlText())
 	}
 
 	return val.Bool(), nil
@@ -196,15 +197,15 @@ func (e *RuleEntry) Evaluate(ctx context.Context, dataContext IDataContext, memo
 func (e *RuleEntry) Execute(ctx context.Context, dataContext IDataContext, memory *WorkingMemory) (err error) {
 	if ctx.Err() != nil {
 
-		return ctx.Err()
+		return fmt.Errorf("context error on executing rule %s. got %w", e.RuleName, ctx.Err())
 	}
 	if e.ThenScope == nil {
 
 		return fmt.Errorf("RuleEntry %s have no then scope", e.RuleName)
 	}
 	defer func() {
 		if r := recover(); r != nil {
-			err = fmt.Errorf("rule engine execute panic ! recovered : %v", r)
+			err = fmt.Errorf("rule engine execute panic on rule %s ! recovered : %v", e.RuleName, r)
 		}
 	}()
 

engine/GruleEngine.go

@@ -218,6 +218,8 @@ func (g *GruleEngine) ExecuteWithContext(ctx context.Context, dataCtx ast.IDataC
 					}
 				}
 			}
+			// set the current rule entry to run. This is for trace ability purpose
+			dataCtx.SetRuleEntry(runner)
 			// notify listeners that we are about to execute a rule entry then scope
 			g.notifyExecuteRuleEntry(cycle, runner)
 			// execute the top most prioritized rule