[ios, macos] Change the format for case expressions to a flat structure. (#11450)

* [ios, macos] Change the format for case expressions to a flat structure.

* [ios, macos] Add support for multiple branches case expression.

* [ios, macos] Add multiple branch tests to case expressions.

* [ios, macos] Case operator now has iOS 8 support.

1 files changed, 22 insertions, 21 deletions

diff --git a/platform/darwin/test/MGLExpressionTests.mm b/platform/darwin/test/MGLExpressionTests.mm
index a5ed2f7bf5..3f36a0cf61 100644
--- a/platform/darwin/test/MGLExpressionTests.mm
+++ b/platform/darwin/test/MGLExpressionTests.mm
@@ -573,28 +573,29 @@ using namespace std::string_literals;
 }
 
 - (void)testConditionalExpressionObject {
-    // FIXME: This test crashes because iOS 8 doesn't have `+[NSExpression expressionForConditional:trueExpression:falseExpression:]`.
-    // https://github.com/mapbox/mapbox-gl-native/issues/11007
-    if (@available(iOS 9.0, *)) {
-        {
-            NSPredicate *conditional = [NSPredicate predicateWithFormat:@"1 = 2"];
-            NSExpression *trueExpression = [NSExpression expressionForConstantValue:@YES];
-            NSExpression *falseExpression = [NSExpression expressionForConstantValue:@NO];
-            NSExpression *expression = [NSExpression expressionForConditional:conditional trueExpression:trueExpression falseExpression:falseExpression];
-            NSArray *jsonExpression = @[@"case", @[@"==", @1, @2], @YES, @NO];
-            XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);
-            XCTAssertEqualObjects([NSExpression expressionWithFormat:@"TERNARY(1 = 2, TRUE, FALSE)"].mgl_jsonExpressionObject, jsonExpression);
-            XCTAssertEqualObjects([expression expressionValueWithObject:nil context:nil], @NO);
-            XCTAssertEqualObjects([NSExpression mgl_expressionWithJSONObject:jsonExpression], expression);
-        }
-        {
-            NSExpression *expression = [NSExpression expressionWithFormat:@"TERNARY(0 = 1, TRUE, TERNARY(1 = 2, TRUE, FALSE))"];
-            NSArray *jsonExpression = @[@"case", @[@"==", @0, @1], @YES, @[@"==", @1, @2], @YES, @NO];
-            XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);
-            XCTAssertEqualObjects([expression expressionValueWithObject:nil context:nil], @NO);
-            XCTAssertEqualObjects([NSExpression mgl_expressionWithJSONObject:jsonExpression], expression);
-        }
+    {
+        NSExpression *expression = [NSExpression expressionWithFormat:@"FUNCTION(%@, 'mgl_case:', %@, %@)",
+                                    [NSExpression expressionWithFormat:@"%@", [NSPredicate predicateWithFormat:@"1 = 2"]],
+                                                                                                 MGLConstantExpression(@YES),
+                                                                                                 MGLConstantExpression(@NO)];
+        NSArray *jsonExpression = @[@"case", @[@"==", @1, @2], @YES, @NO];
+        XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);
+        XCTAssertEqualObjects([NSExpression mgl_expressionWithJSONObject:jsonExpression], expression);
+        XCTAssertEqualObjects([expression expressionValueWithObject:nil context:nil], @NO);
     }
+    {
+        NSExpression *expression = [NSExpression expressionWithFormat:@"FUNCTION(%@, 'mgl_case:', %@, %@, %@, %@)",
+                                    [NSExpression expressionWithFormat:@"%@", [NSPredicate predicateWithFormat:@"1 = 2"]],
+                                                                                                 MGLConstantExpression(@YES),
+                                                                                                 [NSExpression expressionWithFormat:@"%@", [NSPredicate predicateWithFormat:@"1 = 1"]],
+                                                                                                 MGLConstantExpression(@YES),
+                                                                                                 MGLConstantExpression(@NO)];
+        NSArray *jsonExpression = @[@"case", @[@"==", @1, @2], @YES, @[@"==", @1, @1], @YES, @NO];
+        XCTAssertEqualObjects(expression.mgl_jsonExpressionObject, jsonExpression);
+        XCTAssertEqualObjects([NSExpression mgl_expressionWithJSONObject:jsonExpression], expression);
+        XCTAssertEqualObjects([expression expressionValueWithObject:nil context:nil], @YES);
+    }
+    
 }
 
 @end