Code review comment: We usually include `test` in the file. ```suggestion         CompileResult result = BCompileUtil.compile("test-src/klass/resource-method-assignability-negative-test.bal"); ```  Not introduced by this PR, but we use underscores in bal file names.

Code under review:
public void testResourceMethodsDoesNotAffectAssignability() {
        CompileResult result = BCompileUtil.compile("test-src/klass/resource-method-assignability-negative.bal");
        int index = 0;
        validateError(result, index++, "incompatible types: expected 'Foo', found 'Bar'", 38, 13);
        validateError(result, index++, "incompatible types: expected 'Bar', found 'isolated object { " +
                "public function hello () returns (); function foo () returns (int); }'", 40, 15);
        Assert.assertEquals(index, result.getErrorCount());
    }

Line commented on: CompileResult result = BCompileUtil.compile("test-src/klass/resource-method-assignability-negative.bal");

Revised code:
public void testResourceMethodsDoesNotAffectAssignability() {
        CompileResult result = BCompileUtil.compile("test-src/klass/resource_method_assignability_negative_test.bal");
        int index = 0;
        validateError(result, index++, "incompatible types: expected 'Foo', found 'Bar'", 38, 13);
        validateError(result, index++, "incompatible types: expected 'Bar', found 'isolated object { " +
                "public function hello () returns (); function foo () returns (int); }'",
                40, 15);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                ".() returns (); }', found 'isolated object { resource function post .() returns (); }'",
                56, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get [string]() returns (); }'",
                63, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "foo/[int]() returns (); }', found 'isolated object { resource function get foo/[string]() returns " +
                        "(); }'", 70, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get [string]() returns (); }'",
                78, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "foo/[int]() returns (); }', found 'isolated object { resource function get foo/[string]() " +
                        "returns (); }'", 85, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get [byte]() returns (); }'",
                93, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get [string]() returns (); " +
                "resource function post [int]() returns (); }'", 100, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get [string]() returns (); " +
                "resource function post [int]() returns (); }'", 109, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "bar/[int...]() returns (); }', found 'isolated object { resource function get bar/[string...]() " +
                "returns (); }'", 118, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "bar/[int...]() returns (); }', found 'isolated object { resource function get bar/[byte...]() " +
                "returns (); }'", 125, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "bar/[int...]() returns (); }', found 'isolated object { resource function get bar/[int]() " +
                "returns (); }'", 132, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "foo/[int]() returns (); }', found 'isolated object { resource function get foo2/[int]() returns " +
                "(); }'", 139, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "foo/[int]() returns (); }', found 'isolated object { resource function get foo/[string]() returns " +
                "(); }'", 146, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                ".(int) returns (); }', found 'isolated object { resource function get .() returns (); }'",
                153, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                ".() returns (); }', found 'isolated object { resource function get .(int) returns (); }'",
                160, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                ".(int...) returns (); }', found 'isolated object { resource function get .(int) returns (); }'",
                167, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "foo() returns (); }', found 'isolated object { resource function get foo(int) returns (); }'",
                174, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get .(int) returns (); }'",
                181, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int](int) returns (); }', found 'isolated object { resource function get .(int) returns (); }'",
                188, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                ".(int) returns (); }', found 'isolated object { resource function get [int]() returns (); }'",
                195, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                ".(int) returns (); }', found 'isolated object { resource function get [int]() returns (); }'",
                202, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                ".() returns (); }', found 'isolated object { resource function post .() returns (); }'",
                209, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get [string]() returns (); }'",
                216, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "foo/[int]() returns (); }', found 'isolated object { resource function get foo/[string]() returns " +
                "(); }'", 223, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get [string]() returns (); }'",
                230, 11);
        validateError(result, index++, "incompatible types: expected 'object { resource function get " +
                "[int]() returns (); }', found 'isolated object { resource function get [int]() returns (); }'",
                237, 11);

        Assert.assertEquals(index, result.getErrorCount());
    }