KTOR-9406 Add code sample projects for I/O Interoperability

[Seongju-Lee]

Description

Add runnable Gradle subprojects (client-io-interop, server-io-interop) demonstrating the four
adapters documented on the I/O Interoperability page,
migrate the page's inline code blocks to {src=...} references, and add a <tldr> element linking to
both samples.

Verification

• ./gradlew :client-io-interop:run and :server-io-interop:run
• ./gradlew :server-io-interop:test
• Full ./gradlew test --rerun-tasks --continue: no new failures

Related issue

• KTOR-9406

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 683fa5b1-77ac-40d9-bebd-50a14861c522

📥 Commits

Reviewing files that changed from the base of the PR and between d637d8d and de0e3ed.

📒 Files selected for processing (1)

• codeSnippets/snippets/client-io-interop/src/main/kotlin/com/example/Application.kt

🚧 Files skipped from review as they are similar to previous changes (1)

• codeSnippets/snippets/client-io-interop/src/main/kotlin/com/example/Application.kt

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Walkthrough

Adds two new code snippet modules—client-io-interop and server-io-interop—to the Gradle settings, implements a client sample and a server sample (with tests and Logback), adds READMEs for each, and updates topics/io-interoperability.md to include external snippet references to those samples.

Changes

I/O Interoperability Samples

Layer / File(s)	Summary
Gradle Module Registration codeSnippets/settings.gradle.kts	Registers two new snippet submodules: snippets:client-io-interop and snippets:server-io-interop.
Build Configuration codeSnippets/snippets/client-io-interop/build.gradle.kts, codeSnippets/snippets/server-io-interop/build.gradle.kts	Adds Kotlin/JVM application builds, sets com.example.ApplicationKt as main class, configures mavenCentral() and Ktor EAP repo, and declares Ktor/Logback/Kotlin dependencies.
Client Sample Implementation codeSnippets/snippets/client-io-interop/src/main/kotlin/com/example/Application.kt	Adds main() creating a CIO HttpClient, GETs https://httpbin.org/bytes/1024, converts response ByteReadChannel → RawSource via .asSource(), reads and prints the first byte, and closes the client.
Client README codeSnippets/snippets/client-io-interop/README.md	Introduces the sample, describes .asSource() bridging, and provides a run instruction (./gradlew :client-io-interop:run).
Server Sample Implementation codeSnippets/snippets/server-io-interop/src/main/kotlin/com/example/Application.kt	Adds main() and Application.module() starting embedded Netty server on port 8080 with routes /sink, /raw-sink, and /output-stream that write bytes via RawSink, buffer-backed ByteWriteChannel, and OutputStream.asByteWriteChannel() respectively.
Server Build & Resources codeSnippets/snippets/server-io-interop/build.gradle.kts, .../src/main/resources/logback.xml	Adds application build config and Logback config (console appender, root trace, Jetty/Netty INFO).
Server Tests codeSnippets/snippets/server-io-interop/src/test/kotlin/com/example/ApplicationTest.kt	Adds three integration tests using testApplication that call /sink, /raw-sink, and /output-stream, asserting 200 OK and expected response bodies (text or exact bytes).
Server README codeSnippets/snippets/server-io-interop/README.md	Documents the three routes, adapters used (asSink(), RawSink.asByteWriteChannel(), OutputStream.asByteWriteChannel()), run and curl examples.
Docs Update topics/io-interoperability.md	Adds a TLDR linking to the two snippet directories and replaces inline Kotlin examples with external snippet includes referencing the new samples.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• ktorio/ktor-documentation#692 — Also modifies codeSnippets/settings.gradle.kts submodule registrations.
• ktorio/ktor-documentation#707 — Adds/updates IO interoperability samples and related documentation referenced by this change.

Suggested reviewers

• vnikolova
• e5l
• bjhham

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main objective: adding code sample projects for I/O interoperability, which aligns with the changeset of two new Gradle subprojects and documentation updates.
Description check	✅ Passed	The description is directly related to the changeset, explaining the addition of two runnable Gradle subprojects, code migration to external references, and documentation updates, with verification steps included.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In
`@codeSnippets/snippets/client-io-interop/src/main/kotlin/com/example/Application.kt`:
- Around line 13-23: The HttpClient instance (client) is created but never
closed, which can leak engine threads; after the runBlocking { ... } block that
uses client.prepareGet and executes the request, call client.close() to release
resources (ensure the close happens regardless of exceptions—e.g., close client
after runBlocking or use a try/finally around runBlocking) so HttpClient(CIO) is
properly shut down.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: e4b11371-470a-4b84-992b-038831220cf4

📥 Commits

Reviewing files that changed from the base of the PR and between e76df17 and d637d8d.

📒 Files selected for processing (10)

• codeSnippets/settings.gradle.kts
• codeSnippets/snippets/client-io-interop/README.md
• codeSnippets/snippets/client-io-interop/build.gradle.kts
• codeSnippets/snippets/client-io-interop/src/main/kotlin/com/example/Application.kt
• codeSnippets/snippets/server-io-interop/README.md
• codeSnippets/snippets/server-io-interop/build.gradle.kts
• codeSnippets/snippets/server-io-interop/src/main/kotlin/com/example/Application.kt
• codeSnippets/snippets/server-io-interop/src/main/resources/logback.xml
• codeSnippets/snippets/server-io-interop/src/test/kotlin/com/example/ApplicationTest.kt
• topics/io-interoperability.md