http-client-java, support array encoded as CSV on property

[weidongxu-microsoft]

fix #9027

see https://github.com/microsoft/typespec/pull/9218/files#diff-e8b978e5080675f7527d4beb363a9dde604493dbff1db49116ea56c94b2339e1 on difference on generated code.

Currently only supports element as String. (the convert from a subtype to String need some refactor in existing code)

release PR is Azure/autorest.java#3242

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[azure-sdk]

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[Copilot]

Pull request overview

This PR adds support for delimited array encoding (CSV and other formats) on properties in the http-client-java emitter. The implementation allows TypeSpec models to specify how arrays of strings should be serialized as delimited strings in JSON (comma, space, pipe, or newline-delimited) instead of as JSON arrays. The changes span the code generator, model templates, and include both Azure and clientcore test implementations.

Key Changes

• Introduces ArrayEncoding enum to define delimiter strategies for array serialization
• Extends ClientModelProperty to include array encoding metadata
• Updates serialization/deserialization templates to handle delimited string encoding
• Adds validation to ensure only string element types are supported for array encoding

Reviewed changes

Copilot reviewed 22 out of 23 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
packages/http-client-java/package.json	Updates TypeSpec compiler and various dev dependencies to newer versions
packages/http-client-java/package-lock.json	Lockfile updates corresponding to package.json changes
packages/http-client-java/generator/http-client-generator-test/src/test/java/encode/array/EncodeArrayTests.java	New test suite for array encoding with comma, space, pipe, and newline delimiters
packages/http-client-java/generator/http-client-generator-test/src/test/java/azure/clientgenerator/core/clientlocation/ClientLocationClientTests.java	Test file removed (appears to be replaced by generated tests)
packages/http-client-java/generator/http-client-generator-test/src/main/java/encode/array/models/*.java	Generated model classes implementing delimiter-based serialization for different array encoding types
packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/template/StreamSerializationModelTemplate.java	Updates toJson/fromJson generation to handle array encoding with delimiter-based string serialization
packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ClientModelProperty.java	Adds arrayEncoding field to track delimiter configuration
packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/model/clientmodel/ArrayEncoding.java	New enum defining delimiter types and their escape sequences
packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/mapper/ModelPropertyMapper.java	Maps array encoding metadata from TypeSpec model to Java property
packages/http-client-java/generator/http-client-generator-core/src/main/java/com/microsoft/typespec/http/client/generator/core/extension/model/codemodel/Property.java	Adds arrayEncoding field to Property model
packages/http-client-java/generator/http-client-generator-clientcore-test/src/**/*.java	Clientcore test implementations mirroring the Azure test structure
packages/http-client-java/emitter/src/lib.ts	Adds diagnostic for unsupported non-string array encoding elements
packages/http-client-java/emitter/src/common/client.ts	Defines EncodedProperty interface for array encoding metadata
packages/http-client-java/emitter/src/code-model-builder.ts	Validates string element type requirement and maps array encoding to code model

Files not reviewed (1)

• packages/http-client-java/package-lock.json: Language not supported

[haolingdong-msft]

Overall looks good to me. Add a nit. Thanks!