Use shared test data

CHANGELOG.md

@@ -19,6 +19,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+* [Ruby] Empty expression evaluates to true
+
 ## [4.1.0] - 2021-10-08
 
 ### Added

go/.gitignore

@@ -15,3 +15,4 @@ dist_compressed/
 *.iml
 # upx dist/cucumber-gherkin-openbsd-386 fails with a core dump
 core.*.!usr!bin!upx-ucl
+.idea

go/errors_test.go

@@ -0,0 +1,32 @@
+package tagexpressions
+
+import (
+	"fmt"
+	"gopkg.in/yaml.v3"
+	"io/ioutil"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+type ErrorTest struct {
+	Expression string `yaml:"expression"`
+	Error      string `yaml:"error"`
+}
+
+func TestErrors(t *testing.T) {
+	contents, err := ioutil.ReadFile("../testdata/errors.yml")
+	require.NoError(t, err)
+	var tests []ErrorTest
+	err = yaml.Unmarshal(contents, &tests)
+	require.NoError(t, err)
+
+	for _, test := range tests {
+		name := fmt.Sprintf("fails to parse \"%s\" with \"%s\"", test.Expression, test.Error)
+		t.Run(name, func(t *testing.T) {
+			_, err := Parse(test.Expression)
+			require.Error(t, err)
+			require.Equal(t, test.Error, err.Error())
+		})
+	}
+}

go/evaluations_test.go

@@ -0,0 +1,43 @@
+package tagexpressions
+
+import (
+	"fmt"
+	"gopkg.in/yaml.v3"
+	"io/ioutil"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+type Evaluation struct {
+	Expression string `yaml:"expression"`
+	Tests      []Test `yaml:"tests"`
+}
+
+type Test struct {
+	Variables []string `yaml:"variables"`
+	Result    bool     `yaml:"result"`
+}
+
+func TestEvaluations(t *testing.T) {
+	contents, err := ioutil.ReadFile("../testdata/evaluations.yml")
+	require.NoError(t, err)
+	var evaluations []Evaluation
+	err = yaml.Unmarshal(contents, &evaluations)
+	require.NoError(t, err)
+
+	for _, evaluation := range evaluations {
+		for _, test := range evaluation.Tests {
+			variables := strings.Join(test.Variables, ", ")
+			name := fmt.Sprintf("evaluates [%s] to %t", variables, test.Result)
+			t.Run(name, func(t *testing.T) {
+				expression, err := Parse(evaluation.Expression)
+				require.NoError(t, err)
+
+				result := expression.Evaluate(test.Variables)
+				require.Equal(t, test.Result, result)
+			})
+		}
+	}
+}

go/parser.go

@@ -2,7 +2,6 @@ package tagexpressions
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
 	"strings"
 	"unicode"
@@ -27,13 +26,13 @@ func Parse(infix string) (Evaluatable, error) {
 
 	for _, token := range tokens {
 		if isUnary(token) {
-			if err := check(expectedTokenType, OPERAND); err != nil {
+			if err := check(infix, expectedTokenType, OPERAND); err != nil {
 				return nil, err
 			}
 			operators.Push(token)
 			expectedTokenType = OPERAND
 		} else if isBinary(token) {
-			if err := check(expectedTokenType, OPERATOR); err != nil {
+			if err := check(infix, expectedTokenType, OPERATOR); err != nil {
 				return nil, err
 			}
 			for operators.Len() > 0 &&
@@ -45,27 +44,27 @@ func Parse(infix string) (Evaluatable, error) {
 			operators.Push(token)
 			expectedTokenType = OPERAND
 		} else if "(" == token {
-			if err := check(expectedTokenType, OPERAND); err != nil {
+			if err := check(infix, expectedTokenType, OPERAND); err != nil {
 				return nil, err
 			}
 			operators.Push(token)
 			expectedTokenType = OPERAND
 		} else if ")" == token {
-			if err := check(expectedTokenType, OPERATOR); err != nil {
+			if err := check(infix, expectedTokenType, OPERATOR); err != nil {
 				return nil, err
 			}
 			for operators.Len() > 0 && operators.Peek() != "(" {
 				pushExpr(operators.Pop(), expressions)
 			}
 			if operators.Len() == 0 {
-				return nil, errors.New("Syntax error. Unmatched )")
+				return nil, fmt.Errorf("Tag expression \"%s\" could not be parsed because of syntax error: Unmatched ).", infix)
 			}
 			if operators.Peek() == "(" {
 				operators.Pop()
 			}
 			expectedTokenType = OPERATOR
 		} else {
-			if err := check(expectedTokenType, OPERAND); err != nil {
+			if err := check(infix, expectedTokenType, OPERAND); err != nil {
 				return nil, err
 			}
 			pushExpr(token, expressions)
@@ -75,7 +74,7 @@ func Parse(infix string) (Evaluatable, error) {
 
 	for operators.Len() > 0 {
 		if operators.Peek() == "(" {
-			return nil, errors.New("Syntax error. Unmatched (")
+			return nil, fmt.Errorf("Tag expression \"%s\" could not be parsed because of syntax error: Unmatched (.", infix)
 		}
 		pushExpr(operators.Pop(), expressions)
 	}
@@ -157,9 +156,9 @@ func isOp(token string) bool {
 	return ok
 }
 
-func check(expectedTokenType, tokenType string) error {
+func check(infix, expectedTokenType, tokenType string) error {
 	if expectedTokenType != tokenType {
-		return fmt.Errorf("Syntax error. Expected %s", expectedTokenType)
+		return fmt.Errorf("Tag expression \"%s\" could not be parsed because of syntax error: Expected %s.", infix, expectedTokenType)
 	}
 	return nil
 }