Add floating-point-assertEquals-with-integral-values.ql

Author: Marcono1234

codeql-custom-queries-java/queries/unit-tests/floating-point-assertEquals-with-integral-values.ql

@@ -0,0 +1,35 @@
+/**
+ * Finds usage of `assertEquals` and `assertNotEquals` methods with floating point delta
+ * parameter which are used for integral number arguments.
+ * For example `assertEquals(double, double, double)`:
+ * ```java
+ * assertEquals(expectedCount, obj.getCount(), 0);
+ * ```
+ * When the compared arguments are integral numbers the regular `assertEquals` methods should
+ * be used, such as `assertEquals(int, int)`.
+ * 
+ * @kind problem
+ */
+
+import java
+
+// TODO: Maybe use classes from AssertLib.qll?
+from MethodAccess assertCall, Method assertMethod, int argStartIndex, CompileTimeConstantExpr deltaArg
+where
+    assertMethod = assertCall.getMethod()
+    and assertMethod.hasName(["assertEquals", "assertNotEquals"])
+    // Use argStartIndex variable to skip over message parameter, in case there is one
+    and assertMethod.getParameterType(argStartIndex) instanceof FloatingPointType
+    and assertMethod.getParameterType(argStartIndex + 1) instanceof FloatingPointType
+    and assertMethod.getParameterType(argStartIndex + 2) instanceof FloatingPointType
+    and assertCall.getArgument(argStartIndex).getType() instanceof IntegralType
+    and assertCall.getArgument(argStartIndex + 1).getType() instanceof IntegralType
+    // Check delta argument to reduce false positives for intentional usage of this assertion method
+    and deltaArg = assertCall.getArgument(argStartIndex + 2)
+    and (
+        deltaArg.getIntValue() = 0
+        or deltaArg.(LongLiteral).getValue() = "0"
+        or deltaArg.(FloatLiteral).getFloatValue() < 1
+        or deltaArg.(DoubleLiteral).getDoubleValue() < 1
+    )
+select assertCall, "Should not use floating point assertion method for integral arguments"