From b934e181c04a1deb756102898c6bf43d9c3804ca Mon Sep 17 00:00:00 2001
From: Matthew Hague <matthew.hague@rhul.ac.uk>
Date: Sun, 28 Nov 2021 17:46:50 +0000
Subject: [PATCH] Breaking Change: specify call return types
The method call functions in CodeTester now expect an argument giving
the return type. Can use "null" if you don't care.
---
.../uk/ac/rhul/cs/javatester/CodeTester.java | 156 +++++++++---------
.../uk/ac/rhul/cs/javatester/UnitTests.java | 37 +++--
2 files changed, 109 insertions(+), 84 deletions(-)
diff --git a/src/main/java/uk/ac/rhul/cs/javatester/CodeTester.java b/src/main/java/uk/ac/rhul/cs/javatester/CodeTester.java
index 1b81218..a0bfdc7 100644
--- a/src/main/java/uk/ac/rhul/cs/javatester/CodeTester.java
+++ b/src/main/java/uk/ac/rhul/cs/javatester/CodeTester.java
@@ -327,18 +327,14 @@ public class CodeTester {
/**
* Convenience for callMsgAcceptNull with acceptNull set to true
*/
- public Object callMsg(String msg,
- String invocationMsg,
- Object o,
- String methodName,
- Object... params) throws
- BaseTester.FailedTestException {
- return callMsgAcceptNull(msg,
- invocationMsg,
- true,
- o,
- methodName,
- params);
+ public Object callMsg(
+ String msg, String invocationMsg,
+ Class<?> returnType, Object o, String methodName, Object... params
+ ) throws BaseTester.FailedTestException {
+ return callMsgAcceptNull(
+ msg, invocationMsg, true,
+ returnType, o, methodName, params
+ );
}
/**
@@ -354,25 +350,26 @@ public class CodeTester {
* @param invocationMsg failure message prefix in case method call
* throws exception (student code fails)
* @param acceptNull whether the result of the call can be null
+ * @param returnType the expected return type of the method (or null
+ * if don't care)
* @param o the object to call the method on
* @param String name method name
* @param parameterTypes the arguments (cannot be null else type
* can't be inferred, with throw NPE)
* @return the result object
*/
- public Object callMsgAcceptNull(String msg,
- String invocationMsg,
- boolean acceptNull,
- Object o,
- String methodName,
- Object... params) throws
- BaseTester.FailedTestException {
+ public Object callMsgAcceptNull(
+ String msg, String invocationMsg, boolean acceptNull,
+ Class<?> returnType, Object o, String methodName, Object... params
+ ) throws BaseTester.FailedTestException {
Class<?>[] parameterTypes
= Stream.of(params).map(p -> p.getClass())
.toArray(Class<?>[]::new);
try {
Method m = invasiveGetMethod(o, methodName, parameterTypes);
+ checkReturnType(invocationMsg, m, returnType);
+
Object r = invokeMethod(invocationMsg, m, o, params);
if (r == null && !acceptNull) {
@@ -400,27 +397,24 @@ public class CodeTester {
throw new BaseTester.FailedTestException(expandMsg(msg));
}
-
/**
* Convenience for callMsg with default messages.
*
* Will allow method to return null.
*/
- public Object call(Object o,
- String methodName,
- Object... params) throws
- BaseTester.FailedTestException {
- return callAcceptNull(true, o, methodName, params);
+ public Object call(
+ Class<?> returnType, Object o, String methodName, Object... params
+ ) throws BaseTester.FailedTestException {
+ return callAcceptNull(true, returnType, o, methodName, params);
}
/**
* Convenience for callMsgAcceptNull with default messages.
*/
- public Object callAcceptNull(boolean acceptNull,
- Object o,
- String methodName,
- Object... params) throws
- BaseTester.FailedTestException {
+ public Object callAcceptNull(
+ boolean acceptNull,
+ Class<?> returnType, Object o, String methodName, Object... params
+ ) throws BaseTester.FailedTestException {
String base;
if (getLines().size() > 0) {
@@ -435,12 +429,10 @@ public class CodeTester {
String msg = base + "could not be made.";
String invokeMsg = base + "went wrong.";
- return callMsgAcceptNull(msg,
- invokeMsg,
- acceptNull,
- o,
- methodName,
- params);
+ return callMsgAcceptNull(
+ msg, invokeMsg, acceptNull,
+ returnType, o, methodName, params
+ );
}
/**
@@ -500,18 +492,14 @@ public class CodeTester {
/**
* Convenience for callStaticMsgAcceptNull with acceptNull as true
*/
- public Object callStaticMsg(String msg,
- String invocationMsg,
- Class<?> klass,
- String methodName,
- Object... params) throws
- BaseTester.FailedTestException {
- return callStaticMsgAcceptNull(msg,
- invocationMsg,
- true,
- klass,
- methodName,
- params);
+ public Object callStaticMsg(
+ String msg, String invocationMsg,
+ Class<?> returnType, Class<?> klass, String methodName, Object... params
+ ) throws BaseTester.FailedTestException {
+ return callStaticMsgAcceptNull(
+ msg, invocationMsg, true,
+ returnType, klass, methodName, params
+ );
}
/**
@@ -527,18 +515,17 @@ public class CodeTester {
* @param invocationMsg failure message prefix in case method call
* throws exception (student code fails)
* @param acceptNull whether null is an ok return value
+ * @param returnType the expected return type of the method (or
+ * null if don't care)
* @param klass the class having the method
* @param String name method name
* @param parameterTypes the arguments
* @return the result object
*/
- public Object callStaticMsgAcceptNull(String msg,
- String invocationMsg,
- boolean acceptNull,
- Class<?> klass,
- String methodName,
- Object... params) throws
- BaseTester.FailedTestException {
+ public Object callStaticMsgAcceptNull(
+ String msg, String invocationMsg, boolean acceptNull,
+ Class<?> returnType, Class<?> klass, String methodName, Object... params
+ ) throws BaseTester.FailedTestException {
Class<?>[] parameterTypes
= Stream.of(params).map(p -> p.getClass())
.toArray(Class<?>[]::new);
@@ -552,6 +539,8 @@ public class CodeTester {
);
}
+ checkReturnType(msg, m, returnType);
+
Object r = invokeMethod(invocationMsg, m, null, params);
if (r == null && !acceptNull) {
@@ -587,24 +576,22 @@ public class CodeTester {
/**
* Convenience for callMsgAcceptNull with acceptNull as true
*/
- public Object callStatic(Class<?> klass,
- String methodName,
- Object... params) throws
- BaseTester.FailedTestException {
- return callStaticAcceptNull(true,
- klass,
- methodName,
- params);
+ public Object callStatic(
+ Class<?> returnType, Class<?> klass, String methodName, Object... params
+ ) throws BaseTester.FailedTestException {
+ return callStaticAcceptNull(
+ true,
+ returnType, klass, methodName, params
+ );
}
/**
* Convenience for callStaticMsgAcceptNull with default messages.
*/
- public Object callStaticAcceptNull(boolean acceptNull,
- Class<?> klass,
- String methodName,
- Object... params) throws
- BaseTester.FailedTestException {
+ public Object callStaticAcceptNull(
+ boolean acceptNull,
+ Class<?> returnType, Class<?> klass, String methodName, Object... params
+ ) throws BaseTester.FailedTestException {
String base;
if (getLines().size() > 0) {
@@ -619,12 +606,10 @@ public class CodeTester {
String msg = base + "could not be made.";
String invokeMsg = base + "went wrong.";
- return callStaticMsgAcceptNull(msg,
- invokeMsg,
- acceptNull,
- klass,
- methodName,
- params);
+ return callStaticMsgAcceptNull(
+ msg, invokeMsg, acceptNull,
+ returnType, klass, methodName, params
+ );
}
/**
@@ -1167,6 +1152,29 @@ public class CodeTester {
return logIdealizer.apply(output);
}
+ /**
+ * Check the method returns something compatible with returnType
+ *
+ * @param invocationMsg the message to expand in case of failure
+ * @param method the method to check
+ * @param returnType the expected return type
+ * @throws FailedTestException if no match
+ */
+ private void checkReturnType(
+ String invocationMsg, Method method, Class<?> returnType
+ ) throws BaseTester.FailedTestException {
+ if (returnType != null) {
+ if (!isAssignable(method.getReturnType(), returnType)) {
+ throw new BaseTester.FailedTestException(
+ expandMsg(invocationMsg) + "\n\n" +
+ "Expected the method to have a return type compatible with " +
+ getClassString(returnType) +
+ "."
+ );
+ }
+ }
+ }
+
/**
* A class to represent a null argument which can be any object type
*/
diff --git a/src/test/java/uk/ac/rhul/cs/javatester/UnitTests.java b/src/test/java/uk/ac/rhul/cs/javatester/UnitTests.java
index 66db034..41b2065 100644
--- a/src/test/java/uk/ac/rhul/cs/javatester/UnitTests.java
+++ b/src/test/java/uk/ac/rhul/cs/javatester/UnitTests.java
@@ -225,8 +225,9 @@ public class UnitTests {
throws BaseTester.FailedTestException {
CodeTester ct = new CodeTester();
Object node = ct.construct(STORAGE, "value");
- ct.call(node, "setValue", "new val");
- return ct.call(node, "getValue").equals("new val");
+ ct.call(null, node, "setValue", "new val");
+ return ct.call(String.class, node, "getValue")
+ .equals("new val");
}
};
assertTrue(tester.runTests());
@@ -240,13 +241,29 @@ public class UnitTests {
throws BaseTester.FailedTestException {
CodeTester ct = new CodeTester();
Object node = ct.construct(STORAGE, "value");
- ct.call(node, "doesNotExist", "new val");
+ ct.call(null, node, "doesNotExist", "new val");
return true;
}
};
assertFalse(tester.runTests());
}
+ @Test
+ public void testCallMethodWrongReturn() {
+ BaseTester tester = new BaseTester(STORAGE) {
+ @SuppressWarnings("unused")
+ public boolean testCallMethod()
+ throws BaseTester.FailedTestException {
+ CodeTester ct = new CodeTester();
+ Object node = ct.construct(STORAGE, "value");
+ ct.call(int.class, node, "getValue");
+ return true;
+ }
+ };
+ assertFalse(tester.runTests());
+ }
+
+
@Test
public void testOptInOutHasNot() {
BaseTester tester = new BaseTester(SIMPLE_IN_OUT) {
@@ -295,10 +312,10 @@ public class UnitTests {
CodeTester ct = new CodeTester();
Object priv = ct.construct(PRIVATE_CLASS);
ct.construct(PRIVATE_CLASS, "isPrivate");
- ct.call(priv, "privateMethod");
- ct.call(priv, "protectedMethod");
- ct.call(priv, "packageMethod");
- ct.call(priv, "publicMethod");
+ ct.call(null, priv, "privateMethod");
+ ct.call(null, priv, "protectedMethod");
+ ct.call(null, priv, "packageMethod");
+ ct.call(null, priv, "publicMethod");
return true;
}
};
@@ -312,7 +329,7 @@ public class UnitTests {
public boolean testNullPtr() throws FailedTestException {
CodeTester ct = new CodeTester();
Object np = ct.construct(NULL_PTR_CLASS);
- ct.call(np, "nullPtr");
+ ct.call(null, np, "nullPtr");
return true;
}
};
@@ -340,7 +357,7 @@ public class UnitTests {
throws BaseTester.FailedTestException {
CodeTester ct = new CodeTester();
Object o = ct.construct(NULL_PTR_CLASS);
- ct.callAcceptNull(false, o, "getNull");
+ ct.callAcceptNull(false, String.class, o, "getNull");
return true;
}
};
@@ -355,7 +372,7 @@ public class UnitTests {
throws BaseTester.FailedTestException {
CodeTester ct = new CodeTester();
Class<?> klass = ct.loadClass(NULL_PTR_CLASS);
- ct.callStaticAcceptNull(false, klass, "getNull");
+ ct.callStaticAcceptNull(false, String.class, klass, "getNull");
return true;
}
};
--
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