wiremock/wiremock

stub recording should support Content-Encoding: deflate (compression)

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#1,989 opened on Oct 17, 2022

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enhancementhelp wanted

Description

Which version of WireMock you're using: 2.34.0

Steps to reproduce:

  1. Configure a server to compress content with content-encoding: deflate
  2. Record a conversation with this server
  3. Attempt to use this recorded conversation to play back a response

The problem is then that the recorded content is compressed, but the content-encoding: deflate header has been removed. http clients then do not attempt to decompress the content and it is unusable by the application.

This is due to a bug in SutbMappingJsonRecorder: withoutContentEncodingAndContentLength removes these headers always, but the bodyDecompressedIfRequired method only decompresses gzip content. So there is really one bug here (removing headers should be done only if the content encoding is understood and the content is decompressed) and one implied feature request (we should support deflate, it's pretty easy).

Contributor guide

Tech stack
java
Domain
backendtesting
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaHTTP compressionWireMock basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
30
Research direction
The issue is in StubMappingJsonRecorder.java, specifically the withoutContentEncodingAndContentLength method removes headers even when body is not decompressed. The bodyDecompressedIfRequired method currently only handles gzip. To fix, extend that method to support deflate (zlib decompression). Remove content encoding headers only after successful decompression. See also wiremock/wiremock#1989 for details.