Merge branch 'main' into dotnet

Author: clrudolphi

.github/workflows/release-pypi.yaml

@@ -22,7 +22,7 @@ jobs:
         with:
           enable-cache: true
           python-version: "3.14"
-          version: "0.9.7"
+          version: "0.9.8"
 
       - name: Build package
         run: uv build

.github/workflows/test-go.yml

@@ -23,7 +23,7 @@ jobs:
   test-go:
     runs-on: ${{ matrix.os }}
     strategy:
-      fail-fast: false
+      fail-fast: true
       matrix:
         os:
           - ubuntu-latest

.github/workflows/stryker-javascript.yml renamed to .github/workflows/test-javascript-stryker.yml

@@ -1,12 +1,20 @@
-name: stryker-javascript
+name: test-javascript-stryker
 
 on:
   push:
-    branches-ignore:
-      - renovate/**
+    branches:
+      - main
+    paths:
+      - javascript/**
+      - testdata/**
+      - .github/**
   pull_request:
     branches:
       - main
+    paths:
+      - javascript/**
+      - testdata/**
+      - .github/**
 
 jobs:
   stryker-javascript:
@@ -22,7 +30,7 @@ jobs:
       working-directory: javascript
     - run: npm run stryker
       working-directory: javascript
-    - uses: actions/upload-artifact@v4
+    - uses: actions/upload-artifact@v5
       with:
         name: stryker-report
         path: |

.github/workflows/test-python.yml

@@ -35,7 +35,7 @@ jobs:
       with:
         enable-cache: true
         python-version: "3.14"
-        version: "0.9.7"
+        version: "0.9.8"
 
     - name: Linting
       run: uvx ruff check
@@ -67,7 +67,7 @@ jobs:
         with:
           enable-cache: true
           python-version: ${{ matrix.python-version }}
-          version: "0.9.7"
+          version: "0.9.8"
 
       - name: Run tests
         run: uv run pytest

CHANGELOG.md

@@ -6,6 +6,9 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
+### Fixed
+- Render the empty tag expression as an empty string ([#222](https://github.com/cucumber/tag-expressions/pull/222))
+- Improve error message for missing operands ([#221](https://github.com/cucumber/tag-expressions/pull/221))
 
 - [dotNET] Add a .NET implementation
 

go/parser.go

@@ -42,7 +42,9 @@ func Parse(infix string) (Evaluatable, error) {
 				isOp(operators.Peek()) &&
 				((ASSOC[token] == "left" && PREC[token] <= PREC[operators.Peek()]) ||
 					(ASSOC[token] == "right" && PREC[token] < PREC[operators.Peek()])) {
-				pushExpr(operators.Pop(), expressions)
+				if err := pushExpr(infix, operators.Pop(), expressions); err != nil {
+					return nil, err
+				}
 			}
 			operators.Push(token)
 			expectedTokenType = OPERAND
@@ -57,7 +59,9 @@ func Parse(infix string) (Evaluatable, error) {
 				return nil, err
 			}
 			for operators.Len() > 0 && operators.Peek() != "(" {
-				pushExpr(operators.Pop(), expressions)
+				if err := pushExpr(infix, operators.Pop(), expressions); err != nil {
+					return nil, err
+				}
 			}
 			if operators.Len() == 0 {
 				return nil, fmt.Errorf("Tag expression \"%s\" could not be parsed because of syntax error: Unmatched ).", infix)
@@ -70,7 +74,9 @@ func Parse(infix string) (Evaluatable, error) {
 			if err := check(infix, expectedTokenType, OPERAND); err != nil {
 				return nil, err
 			}
-			pushExpr(token, expressions)
+			if err := pushExpr(infix, token, expressions); err != nil {
+				return nil, err
+			}
 			expectedTokenType = OPERATOR
 		}
 	}
@@ -79,7 +85,9 @@ func Parse(infix string) (Evaluatable, error) {
 		if operators.Peek() == "(" {
 			return nil, fmt.Errorf("Tag expression \"%s\" could not be parsed because of syntax error: Unmatched (.", infix)
 		}
-		pushExpr(operators.Pop(), expressions)
+		if err := pushExpr(infix, operators.Pop(), expressions); err != nil {
+			return nil, err
+		}
 	}
 
 	return expressions.Pop(), nil
@@ -153,24 +161,51 @@ func check(infix, expectedTokenType, tokenType string) error {
 	return nil
 }
 
-func pushExpr(token string, stack *EvaluatableStack) {
+func pushExpr(infix string, token string, stack *EvaluatableStack) error {
 	if token == "and" {
-		rightAndExpr := stack.Pop()
+		rightAndExpr, err := popOperand(infix, stack)
+		if err != nil {
+			return err
+		}
+		leftAndExpr, err := popOperand(infix, stack)
+		if err != nil {
+			return err
+		}
 		stack.Push(&andExpr{
-			leftExpr:  stack.Pop(),
+			leftExpr:  leftAndExpr,
 			rightExpr: rightAndExpr,
 		})
 	} else if token == "or" {
-		rightOrExpr := stack.Pop()
+		rightOrExpr, err := popOperand(infix, stack)
+		if err != nil {
+			return err
+		}
+		leftOrExpr, err := popOperand(infix, stack)
+		if err != nil {
+			return err
+		}
 		stack.Push(&orExpr{
-			leftExpr:  stack.Pop(),
+			leftExpr:  leftOrExpr,
 			rightExpr: rightOrExpr,
 		})
 	} else if token == "not" {
-		stack.Push(&notExpr{expr: stack.Pop()})
+		expr, err := popOperand(infix, stack)
+		if err != nil {
+			return err
+		}
+		stack.Push(&notExpr{expr: expr})
 	} else {
 		stack.Push(&literalExpr{value: token})
 	}
+
+	return nil
+}
+
+func popOperand(infix string, stack *EvaluatableStack) (Evaluatable, error) {
+	if stack.Len() > 0 {
+		return stack.Pop(), nil
+	}
+	return nil, fmt.Errorf("Tag expression \"%s\" could not be parsed because of syntax error: Expected operand.", infix)
 }
 
 type literalExpr struct {
@@ -249,5 +284,5 @@ func (t *trueExpr) Evaluate(variables []string) bool {
 }
 
 func (t *trueExpr) ToString() string {
-	return "true"
+	return ""
 }

java/pom.xml

@@ -33,7 +33,7 @@
             <dependency>
                 <groupId>org.junit</groupId>
                 <artifactId>junit-bom</artifactId>
-                <version>6.0.0</version>
+                <version>6.0.1</version>
                 <type>pom</type>
                 <scope>import</scope>
             </dependency>

java/src/main/java/io/cucumber/tagexpressions/TagExpressionParser.java

@@ -52,7 +52,7 @@ private Expression parse() {
                                 ||
                                 (ASSOC.get(token) == Assoc.RIGHT && PREC.get(token) < PREC.get(operators.peek())))
                 ) {
-                    pushExpr(pop(operators), expressions);
+                    pushExpr(operators.pop(), expressions);
                 }
                 operators.push(token);
                 expectedTokenType = TokenType.OPERAND;
@@ -63,13 +63,13 @@ private Expression parse() {
             } else if (")".equals(token)) {
                 check(expectedTokenType, TokenType.OPERATOR);
                 while (operators.size() > 0 && !"(".equals(operators.peek())) {
-                    pushExpr(pop(operators), expressions);
+                    pushExpr(operators.pop(), expressions);
                 }
                 if (operators.size() == 0) {
                     throw new TagExpressionException("Tag expression \"%s\" could not be parsed because of syntax error: Unmatched ).", this.infix);
                 }
                 if ("(".equals(operators.peek())) {
-                    pop(operators);
+                    operators.pop();
                 }
                 expectedTokenType = TokenType.OPERATOR;
             } else {
@@ -83,7 +83,7 @@ private Expression parse() {
             if ("(".equals(operators.peek())) {
                 throw new TagExpressionException("Tag expression \"%s\" could not be parsed because of syntax error: Unmatched (.", infix);
             }
-            pushExpr(pop(operators), expressions);
+            pushExpr(operators.pop(), expressions);
         }
 
         return expressions.pop();
@@ -128,31 +128,34 @@ private void check(TokenType expectedTokenType, TokenType tokenType) {
         }
     }
 
-    private <T> T pop(Deque<T> stack) {
-        if (stack.isEmpty())
-            throw new TagExpressionException("Tag expression \"%s\" could not be parsed because of an empty stack", infix);
-        return stack.pop();
-    }
-
-    private void pushExpr(String token, Deque<Expression> stack) {
+    private void pushExpr(String token, Deque<Expression> expressions) {
         switch (token) {
             case "and":
-                Expression rightAndExpr = pop(stack);
-                stack.push(new And(pop(stack), rightAndExpr));
+                Expression rightAndExpr = popOperand(expressions);
+                Expression leftAndExpr = popOperand(expressions);
+                expressions.push(new And(leftAndExpr, rightAndExpr));
                 break;
             case "or":
-                Expression rightOrExpr = pop(stack);
-                stack.push(new Or(pop(stack), rightOrExpr));
+                Expression rightOrExpr = popOperand(expressions);
+                Expression leftOrExpr = popOperand(expressions);
+                expressions.push(new Or(leftOrExpr, rightOrExpr));
                 break;
             case "not":
-                stack.push(new Not(pop(stack)));
+                Expression expression = popOperand(expressions);
+                expressions.push(new Not(expression));
                 break;
             default:
-                stack.push(new Literal(token));
+                expressions.push(new Literal(token));
                 break;
         }
     }
 
+    private <T> T popOperand(Deque<T> stack) {
+        if (stack.isEmpty())
+            throw new TagExpressionException("Tag expression \"%s\" could not be parsed because of syntax error: Expected operand.", infix);
+        return stack.pop();
+    }
+    
     private boolean isUnary(String token) {
         return "not".equals(token);
     }
@@ -267,7 +270,7 @@ public boolean evaluate(List<String> variables) {
 
         @Override
         public String toString() {
-            return "true";
+            return "";
         }
     }
 }

javascript/package-lock.json

@@ -50,7 +50,7 @@
     "@stryker-mutator/typescript-checker": "9.3.0",
     "@types/js-yaml": "^4.0.3",
     "@types/mocha": "10.0.10",
-    "@types/node": "22.18.13",
+    "@types/node": "22.19.0",
     "@typescript-eslint/eslint-plugin": "^8.46.0",
     "@typescript-eslint/parser": "^8.46.0",
     "eslint": "^9.21.0",
@@ -59,7 +59,7 @@
     "eslint-plugin-simple-import-sort": "^12.1.1",
     "globals": "^16.0.0",
     "js-yaml": "^4.1.0",
-    "mocha": "11.7.4",
+    "mocha": "11.7.5",
     "prettier": "^3.5.2",
     "pretty-quick": "4.2.2",
     "ts-node": "10.9.2",