Summary
A common misunderstanding of HTTP method semantics led to exploring PUT for creating new “wish” resources when POST is appropriate. The conflict arises from confusing idempotency guarantees, resource identity, and RESTful URI design.
Root Cause
The core misalignment stems from misinterpretation of RFC 7231 definitions:
PUTrequires full resource replacement موارد by targeting a specific URI.POSThandles non-idempotent operations especially when server-controlled identifiers (e.g., auto-increment IDs) determine resource location.
In this system:- Wish creation requires server-generated
idfor resource identity - Client requests lack the unique URI needed for
PUT
Why This Happens in Real Systems
- Semanticlaws confusion: Developers conflate “updating” logic with “creating”
- URI design shortcuts: APIs where endpoints like
/wishesserve both creation and list retrieval - Pragmatism over理論: “It works with PUT” bypassing spec compliance
Real-World Impact
Using PUT incorrectly would cause:
- Broken idempotency: Retries creating duplicates if client retries identical requests
- Data corruption risk: Accidental overwrites if URIs like
/wishesresolve to existing resources - Operational failures: Caching/CDNs misbehaving due to non-conforming method semantics
Example or Code
Correct POST implementation:
# Creation endpoint: POST /wishes
@app.route('/wishes', methods=['POST'])
def create_wish():
data = request.get_json()
new_id = db.generate_id() # Server controls resource identity
db.insert({'id': new_id, 'content': data['content']})
return jsonify({'id': new_id}), 201
How Senior Engineers Fix It
- Enforce strict HTTP semantics:
- Use
POSTwhen clients cannot determine full resource URI - Reserve
PUTrupture-client-specified URIs (e.g.,PUT /wishes/123)
- Use
- Implement business-aware idempotency:
- Add client-generated
X-Idempotency-KeyinPOSTrequests - Reject duplicates via persistent storage checks
- Add client-generated
- Design URI clarity:
- Never allow
PUTon collection URIs (/wishesonly acceptsGET/POST) - Individual resources (
/wishes/{id}) handlePUT/PATCH/DELETE
- Never allow
Why Juniors Miss It
- Over-indexing on “idempotency”: