feat(local-server-stress-tests): add support for dynamic generator weights

[anthony-murphy-agent]

Summary

• Add dynamicWeightGenerator.ts with createWeightedAsyncGeneratorWithDynamicWeights
• Enable generator weights to be functions that receive state and return a weight
• This allows weights to vary based on the current test state

The standard createWeightedAsyncGenerator from stochastic-test-utils only supports static numeric weights. This enhancement enables dynamic weighting based on runtime conditions like container attach state.

Test plan

• local-server-stress-tests pass
• No breaking changes to existing behavior (weights can still be static numbers)

🤖 Generated with Claude Code

[anthony-murphy-agent]

Azure Pipelines commands (copy and post separately, limit of 10 at a time):

/azp run Build - api-markdown-documenter, Build - benchmark-tool, Build - build-common, Build - build-tools, Build - client packages, Build - common-utils, Build - eslint-config-fluid, Build - eslint-plugin-fluid, Build - protocol-definitions, Build site

/azp run Build - test-tools, repo-policy-check, server-gitrest, server-gitssh, server-historian, server-routerlicious

[anthony-murphy]

/azp run Build - api-markdown-documenter, Build - benchmark-tool, Build - build-common, Build - build-tools, Build - client packages, Build - common-utils, Build - eslint-config-fluid, Build - eslint-plugin-fluid, Build - protocol-definitions, Build site

[anthony-murphy]

/azp run Build - test-tools, repo-policy-check, server-gitrest, server-gitssh, server-historian, server-routerlicious

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[azure-pipelines]

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[Copilot]

Pull request overview

This PR adds infrastructure for dynamic weight functions in weighted random generators for the local-server-stress-tests package. Currently, the stochastic-test-utils library only supports static numeric weights, but this enhancement enables weights that can be computed dynamically based on runtime test state.

Changes:

• Introduces dynamicWeightGenerator.ts with support for both static and dynamic (function-based) weights
• Updates baseModel.ts to use the new dynamic weight generator instead of the static one from stochastic-test-utils
• Maintains full backward compatibility - existing code with static weights continues to work

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/test/local-server-stress-tests/src/dynamicWeightGenerator.ts	New module implementing createWeightedAsyncGeneratorWithDynamicWeights, a variant of the stochastic-test-utils function that evaluates weight functions dynamically at runtime
packages/test/local-server-stress-tests/src/baseModel.ts	Updated to use the new dynamic weight generator, with type changes from AsyncWeights to DynamicAsyncWeights

[Copilot]

The arrow in the JSDoc comment is escaped with a backslash. Remove the backslash so it renders correctly as (state) => number instead of (state) =\> number.

Suggested change

	* weight can be a number or a function (state) =\> number
	* weight can be a number or a function (state) => number

[anthony-murphy-agent]

Thanks for the suggestion! However, the backslash escape is actually required here. The project uses TSDoc and has an ESLint rule (tsdoc/syntax) that requires the > character to be escaped to avoid confusion with HTML tags. If I remove the backslash, the build fails with:

tsdoc-escape-greater-than: The ">" character should be escaped using a backslash to avoid confusion with an HTML tag

So the escaped version =\> is correct for TSDoc, even though it may look slightly odd in the rendered documentation.