DOC-7170 Add compare-and-swap/compare-and-delete example to the strings page

[andy-stark-redis]

Adds a compare-and-swap / compare-and-delete example (Redis 8.4 SET ... IFEQ and DELEX ... IFEQ) to the strings data type page, and refreshes the command-API mappings for SET, DELEX, and DIGEST. Jira: DOC-7170

Changes

• strings/_index.md: new cas_cad step after setnx_xx, with short prose linking SET, DELEX, and DIGEST. The setnx_xx description no longer calls NX/XX "compare-and-set".
• Client examples in local_examples/ for Python, Node.js, Jedis, Lettuce async and reactive, Go, SE.Redis, PHP, Rust sync and async.
• Ruby is excluded with a lang_filter allowlist. redis-rb 6.0.0 doesn't ship ifeq:/delex; they're on master only.
• API mappings:
  • SET: adds go-redis SetArgs and SetIFEQ/SetIFNE/SetIFDEQ/SetIFDNE, plus redis-rs set_options.
  • DELEX: adds node-redis and redis-rs.
  • DIGEST: adds Jedis and node-redis. Replaces the wrong Lettuce rows: they were the Lua-script SHA1 digest(String script), not the DIGEST command (digestKey).
  • Clears an invented Jedis delex return description.
• PHP setnx_xx: fixes the same wrong // >>> (null) output comment in the existing step; it now uses var_export and NULL.
• TCE skill: testing.md now closes stdin on the documented codex exec command and covers the capacity retry and one-client-per-verdict schema.
• Harness: bumps the StackExchange.Redis pin from 3.0.0 to 3.3.1. In 3.0.0, ValueCondition is [Experimental], so it fails the build with SER002.

Verification

• All 11 set_tutorial clients pass in the portable harness against Redis 8.8 (Ruby's existing steps included). The CLI block was checked against the live server.
• Hugo build: the new block renders 10 client tabs plus the CLI tab, with no Ruby tab and no leaked scaffolding.
• Codex reviewed each client file. One high finding was fixed: the PHP null output comment. One was declined: Rust .expect(), which matches the existing visible step.

Follow-ups

• Add Ruby once redis-rb releases ifeq:/delex/digest.

🤖 Generated with Claude Code

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Note

Low Risk
Documentation, generated examples, and API metadata updates with a test-harness dependency bump; no production runtime or auth changes.

Overview
Adds compare-and-swap / compare-and-delete documentation for Redis 8.4 (SET … IFEQ, DELEX … IFEQ) on the strings data-type page, including a new cas_cad tabbed example (Ruby omitted via lang_filter until redis-rb ships support).

Docs & examples: New prose and CLI block on strings/_index.md; the setnx_xx blurb no longer labels NX/XX as compare-and-set. Matching cas_cad steps land in Python, Node, Jedis, Lettuce async/reactive, Go, SE.Redis, PHP, and Rust sync/async. PHP also fixes setnx_xx null output to use var_export / NULL.

API mappings: Extends SET (go-redis conditional helpers, redis-rs set_options), DELEX (node-redis, redis-rs), and DIGEST (Jedis/node-redis; Lettuce entries corrected from script SHA1 digest to key digestKey). Clears incorrect Jedis delex return text.

Tooling: Bumps StackExchange.Redis in the dotnet harness to 3.3.1 so ValueCondition is not experimental. TCE testing guide documents codex exec pitfalls (< /dev/null, capacity errors, one client per invocation, unsandboxed $TMPDIR).

^{Reviewed by Cursor Bugbot for commit d6b91b1. Bugbot is set up for automated code reviews on this repo. Configure here.}

[github-actions]

DOC-7170

[github-actions]

Staging links:
https://redis.io/docs/staging/DOC-7170/develop/data-types/strings/

[github-actions]

🧠 Redis Memory

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• Commit — DOC-7170 Add compare-and-swap/compare-and-delete example to the strings page 🆕

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  What

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Memory updated at d6b91b1