Add flag: returnBool for property testing

docs/src/project_configuration/testing_config.md

@@ -177,6 +177,15 @@ contract MyContract {
   > **Note**: If you are moving over from Echidna, you can add `echidna_` as a test prefix to quickly port over the property tests from it.
 - **Default**: `[property_]`
 
+
+### `returnBool`
+
+- **Type**: [Bool]
+- **Description**: If the property returns a boolean or not
+  > **Note**: If you are using invariants developed for Foundry's invariant testing, set this to false.
+- **Default**: `true`
+
+
 ## Optimization Testing Configuration
 
 ### `enabled`

docs/src/static/function_level_testing_medusa.json

@@ -40,7 +40,8 @@
       },
       "propertyTesting": {
         "enabled": true,
-        "testPrefixes": ["property_"]
+        "testPrefixes": ["property_"],
+        "returnBool": true
       },
       "optimizationTesting": {
         "enabled": true,

docs/src/static/medusa.json

@@ -44,7 +44,8 @@
       },
       "propertyTesting": {
         "enabled": true,
-        "testPrefixes": ["property_"]
+        "testPrefixes": ["property_"],
+        "returnBool": true
       },
       "optimizationTesting": {
         "enabled": true,

docs/src/testing/writing-tests.md

@@ -12,6 +12,7 @@ For more advanced information and documentation on how the various modes work an
 
 Property tests are represented as functions within a Solidity contract whose names are prefixed with a prefix specified by the `testPrefixes` configuration option (`fuzz_` is the default test prefix). Additionally, they must take no arguments and return a `bool` indicating if the test succeeded.
 
+
 ```solidity
 contract TestXY {
     uint x;
@@ -34,6 +35,8 @@ contract TestXY {
 
 `medusa` deploys your contract containing property tests and generates a sequence of calls to execute against all publicly accessible methods. After each function call, it calls upon your property tests to ensure they return a `true` (success) status.
 
+If you are using [Foundry's invariant testing](https://getfoundry.sh/forge/advanced-testing/invariant-testing/#conditional-invariants), you can define the properties to not return a boolean by setting `returnBool` to false.
+
 ### Testing in property-mode
 
 To begin a fuzzing campaign in property-mode, you can run `medusa fuzz` or `medusa fuzz --config [config_path]`.

fuzzing/config/config.go

@@ -310,6 +310,9 @@ type PropertyTestingConfig struct {
 
 	// TestPrefixes dictates what method name prefixes will determine if a contract method is a property test.
 	TestPrefixes []string `json:"testPrefixes"`
+
+	// TestReturnBool dictactes if the properties should return a bool or not
+	TestReturnBool bool `json:"returnBool"`
 }
 
 // OptimizationTestingConfig describes the configuration options used for optimization testing

fuzzing/config/config_defaults.go

@@ -83,6 +83,7 @@ func GetDefaultProjectConfig(platform string) (*ProjectConfig, error) {
 					TestPrefixes: []string{
 						"property_",
 					},
+					TestReturnBool: true,
 				},
 				OptimizationTesting: OptimizationTestingConfig{
 					Enabled: true,

fuzzing/fuzzer.go

@@ -411,7 +411,8 @@ func (f *Fuzzer) AddCompilationTargets(compilations []compilationTypes.Compilati
 				assertionTestMethods, propertyTestMethods, optimizationTestMethods := fuzzingutils.BinTestByType(&contract,
 					f.config.Fuzzing.Testing.PropertyTesting.TestPrefixes,
 					f.config.Fuzzing.Testing.OptimizationTesting.TestPrefixes,
-					f.config.Fuzzing.Testing.TestViewMethods)
+					f.config.Fuzzing.Testing.TestViewMethods,
+					f.config.Fuzzing.Testing.PropertyTesting.TestReturnBool)
 				contractDefinition.AssertionTestMethods = assertionTestMethods
 				contractDefinition.PropertyTestMethods = propertyTestMethods
 				contractDefinition.OptimizationTestMethods = optimizationTestMethods

fuzzing/test_case_property_provider.go

@@ -102,6 +102,11 @@ func (t *PropertyTestCaseProvider) checkPropertyTestFailed(worker *FuzzerWorker,
 		return true, executionTrace, nil
 	}
 
+	// If the properties don't have a return value
+	if !worker.fuzzer.config.Fuzzing.Testing.PropertyTesting.TestReturnBool {
+		return false, executionTrace, nil
+	}
+
 	// Decode our ABI outputs
 	retVals, err := propertyTestMethod.Method.Outputs.Unpack(executionResult.Return())
 	if err != nil {

fuzzing/utils/fuzz_method_utils.go

@@ -24,12 +24,16 @@ func IsOptimizationTest(method abi.Method, prefixes []string) bool {
 
 // IsPropertyTest checks whether the method is a property test given potential naming prefixes it must conform to
 // and its underlying input/output arguments.
-func IsPropertyTest(method abi.Method, prefixes []string) bool {
+func IsPropertyTest(method abi.Method, prefixes []string, propertyTestReturnBool bool) bool {
 	// Loop through all enabled prefixes to find a match
 	for _, prefix := range prefixes {
 		// The property test must simply have the right prefix and take no inputs and return a boolean
 		if strings.HasPrefix(method.Name, prefix) {
-			if len(method.Inputs) == 0 && len(method.Outputs) == 1 && method.Outputs[0].Type.T == abi.BoolTy {
+			// If returnBool is set to true, the property return a boolean, otherwise it return nothing
+			if len(method.Inputs) == 0 && len(method.Outputs) == 1 && method.Outputs[0].Type.T == abi.BoolTy && propertyTestReturnBool {
+				return true
+			}
+			if len(method.Inputs) == 0 && len(method.Outputs) == 0 && !propertyTestReturnBool {
 				return true
 			}
 		}
@@ -38,9 +42,9 @@ func IsPropertyTest(method abi.Method, prefixes []string) bool {
 }
 
 // BinTestByType sorts a contract's methods by whether they are assertion, property, or optimization tests.
-func BinTestByType(contract *compilationTypes.CompiledContract, propertyTestPrefixes, optimizationTestPrefixes []string, testViewMethods bool) (assertionTests, propertyTests, optimizationTests []abi.Method) {
+func BinTestByType(contract *compilationTypes.CompiledContract, propertyTestPrefixes, optimizationTestPrefixes []string, testViewMethods bool, propertyTestReturnBool bool) (assertionTests, propertyTests, optimizationTests []abi.Method) {
 	for _, method := range contract.Abi.Methods {
-		if IsPropertyTest(method, propertyTestPrefixes) {
+		if IsPropertyTest(method, propertyTestPrefixes, propertyTestReturnBool) {
 			propertyTests = append(propertyTests, method)
 		} else if IsOptimizationTest(method, optimizationTestPrefixes) {
 			optimizationTests = append(optimizationTests, method)