What is JSON?

Part A has nine syntax errors. Line 2: a comment; JSON has none. Line 4: 'SAR' uses single quotes; write "SAR". Line 5: the key items is not quoted; write "items". Line 7 holds three errors: 01 has a leading zero (write 1), 42. ends with a decimal point (write 42 or 42.00), and the comma after the last array element must go. Line 9: False must be lower case, false. Line 11 holds two: the inner double quotes end the string early, so escape them with backslashes, "Leave it at the gate marked \"B\"", and the comma after the last member of the object must go.

Lines 1, 3, 6, 8, 10 and 12 are valid. 6.50 is a correct number (zeros after the decimal point are allowed), null is a valid value, and a comma is an error only after the last element, so the comma at the end of line 6 is fine. Delete the comment instead of turning it into a key such as "_comment": the fixture is the request body, so any extra key is sent to the API too. Put the note in the test name or description.

The validator needs nine rounds, one per error in the order of the list above, because a parser stops at the first error it meets. Go by the line and column, which mark where the parser stopped: a hint is a guess made from the text around that point, so check it against the rules. Once you delete the comment line, every later line number moves up by one. The two trailing commas are often reported at the closing bracket on the next line, where the parser notices them. So one reported error never means "one error": read the whole document against the rules first and use the validator to confirm. Note also that the failing test said nothing about the API: the defect was in the testware, so you fix the fixture and do not report a defect against the API.

Part C, types: orderId, status and customer.id are strings; customer.phone is a number; items is an array of two objects whose sku values are strings; quantity is a string ("2") in the first item and a number (0) in the second; both unitPrice values and total are numbers; giftWrap is a string; couponCode is null. deliveredAt is missing.

Correct: orderId, customer.id, items (an array of two objects), both sku values, both unitPrice values, couponCode, and the type and format of total (its value is checked below). A JSON number is a value, not a display format: 6.5 and 6.50 are the same number and 42 is a valid number, so showing "6.50 SAR" is the job of the screen. null is allowed for couponCode and means that no coupon was used.

Deviations, all caught by schema validation and none by syntax validation, because the response is valid JSON: (1) status is "Paid"; strings are compared exactly, so a client that checks for "paid" does not see a paid order (allowed values, an enum). (2) customer.phone is the number 501234567; a JSON number cannot have a leading zero, so a phone number sent as a number always loses it (type string, pattern). (3) items[0].quantity is the string "2"; in JavaScript "2" + 1 gives "21", so a cart that adds one more item shows 21 (type integer). (4) items[1].quantity is 0, below the minimum of 1 (minimum). (5) giftWrap is the string "false"; every non-empty string is truthy in JavaScript, so if (order.giftWrap) treats the order as gift-wrapped (type boolean). (6) deliveredAt is missing; a missing key is not null, and order.deliveredAt === null is false because the value is undefined (required).

The expression $.items[*].quantity returns "2" with type string and 0 with type number, so both quantity deviations show up in one query, and an automated test would assert on the same path. The Type column says number, not integer: JSON has a single number type, and "integer" is a rule of the contract (JSON Schema has an integer type for it). The API Response Analyzer points to some deviations without any contract (the quantity sent as a string and with a different type in each item, giftWrap sent as a string), but it cannot know that the status spelling, the phone number, the missing key or the zero quantity are wrong. Only the contract tells you that.

Neither level: the corrected request ordered 2 × 6.50 + 1 × 42.00 = 55.00 SAR, and total is 55, which matches. The items in the response, however, add up to 2 × 6.5 + 0 × 42 = 13, so they break the contract rule that total is their sum, and the comparison with the request shows that the quantity of RCE-5KG is wrong, not the total. A schema checks each value on its own; it cannot check a sum across fields or compare the response with what was ordered. Had the server returned a quantity of 3, every schema rule would pass. That needs a test oracle, a source of the expected result, here the request: calculate the expected values from it and compare them in an assertion. Report each deviation with the field path, the expected and the actual value, for example "items[0].quantity: expected an integer of 1 or more, actual the string "2"", and attach the request and the response.