Add DURABLE0011: ContinueAsNew warning for unbounded orchestration loops

[torosent]

Summary

Adds a new Roslyn analyzer DURABLE0011 that warns when an orchestration contains a while(true) loop that calls any TaskOrchestrationContext method but has no ContinueAsNew call within that loop.

Problem this addresses

Long-lived orchestrations that run in unbounded loops accumulate history without limit. Every TaskOrchestrationContext method call (e.g. CallActivityAsync, WaitForExternalEvent, CallSubOrchestratorAsync, CreateTimer) adds to the replay history. This leads to increasingly expensive replays and can cause backend persistence failures. This was identified as the root cause of a production crash loop in the Durable Task Scheduler.

What is included

• ContinueAsNewOrchestrationAnalyzer.cs -- Roslyn analyzer (ID: DURABLE0011)
• Resource strings in Resources.resx
• Release tracking entry in AnalyzerReleases.Unshipped.md
• Test class with 9 test cases (all passing)

Detection rules

Flagged	Not flagged
while(true) + any context method + no ContinueAsNew	while(true) + ContinueAsNew present
while(true) + CallActivityAsync + no ContinueAsNew	No while(true) loop
while(true) + WaitForExternalEvent + no ContinueAsNew	while(true) with no context method calls
while(true) + CallSubOrchestratorAsync + no ContinueAsNew

Implementation

• Uses semantic IOperation analysis to verify methods are on TaskOrchestrationContext (no false positives from identically-named methods on other types)
• Detects any TaskOrchestrationContext method call (except ContinueAsNew itself) as history-growing
• Initialize() validates TaskOrchestrationContext symbol is available before running
• Analyzer class is sealed per repo conventions

Testing

• 152 total tests pass, 0 skipped, 0 regressions
• 9 new tests: 4 positive-detection + 5 no-diagnostic cases

Verification

[Copilot]

Pull request overview

Adds a new Roslyn analyzer rule (DURABLE0011) to warn about orchestrations that use unbounded while(true) loops with history-growing operations (WaitForExternalEvent / CallSubOrchestratorAsync) but do not call ContinueAsNew, helping prevent unbounded history growth and replay degradation in Durable Task orchestrations.

Changes:

• Introduces ContinueAsNewOrchestrationAnalyzer (DURABLE0011) to detect problematic unbounded orchestration loops.
• Adds localized resource strings (title + message) for the new analyzer.
• Adds release tracking metadata and a new test class (with several diagnostic tests currently skipped).

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
test/Analyzers.Tests/Orchestration/ContinueAsNewOrchestrationAnalyzerTests.cs	Adds test coverage for DURABLE0011 scenarios (positive cases currently skipped).
src/Analyzers/Resources.resx	Adds title/message resource strings for DURABLE0011.
src/Analyzers/Orchestration/ContinueAsNewOrchestrationAnalyzer.cs	Implements the DURABLE0011 analyzer logic.
src/Analyzers/AnalyzerReleases.Unshipped.md	Registers DURABLE0011 in analyzer release tracking.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 4 changed files in this pull request and generated 4 comments.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 5 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 5 changed files in this pull request and generated 4 comments.

[Copilot]

Pull request overview

Copilot reviewed 4 out of 5 changed files in this pull request and generated 2 comments.

[YunchuWang]

helpLinkUri inconsistent with all other analyzers
Severity: Medium
Priority: P1
Confidence: High
Category: API and Contract Safety
Location: ContinueAsNewOrchestrationAnalyzer.cs — helpLinkUri: "https://aka.ms/durabletask-analyzers"
Why this matters: All 15 existing analyzer rules use "https://go.microsoft.com/fwlink/?linkid=2346202". The aka.ms link may resolve differently and creates an inconsistency visible to users in the IDE warning tooltip. If this was a deliberate decision to start migrating to a new URL, it should be documented; otherwise it should match existing rules.
Evidence: Every other helpLinkUri in src/Analyzers/**/*.cs uses the fwlink URL.
Recommendation: Change to helpLinkUri: "https://go.microsoft.com/fwlink/?linkid=2346202" unless the team intentionally wants to move all analyzers to the new link (in which case do it in a separate PR for all rules).
Publish target: inline

[torosent]

helpLinkUri inconsistent with all other analyzers Severity: Medium Priority: P1 Confidence: High Category: API and Contract Safety Location: ContinueAsNewOrchestrationAnalyzer.cs — helpLinkUri: "https://aka.ms/durabletask-analyzers" Why this matters: All 15 existing analyzer rules use "https://go.microsoft.com/fwlink/?linkid=2346202". The aka.ms link may resolve differently and creates an inconsistency visible to users in the IDE warning tooltip. If this was a deliberate decision to start migrating to a new URL, it should be documented; otherwise it should match existing rules. Evidence: Every other helpLinkUri in src/Analyzers/**/*.cs uses the fwlink URL. Recommendation: Change to helpLinkUri: "https://go.microsoft.com/fwlink/?linkid=2346202" unless the team intentionally wants to move all analyzers to the new link (in which case do it in a separate PR for all rules). Publish target: inline

Need to update the other analyzers. This is the wrong link