Template servers: Java HTML generation

[t1]

Parent: #40 (Template server variables and presets)

Generate HTML structure for servers with template variables ({variable} placeholders).

Scope

Template detection:

• Check if server URL contains {variable} placeholders via server.getVariables()
• Extract variable metadata: name, default value, enum values, description

HTML structure:

• Template server displayed as URL pattern heading (e.g., https://api.{environment}.example.com)
• Nested indented preset radio buttons below (not flat like static servers)
• Default preset auto-generated when all variables have defaults (labeled with resolved URL)
• Variable metadata stored in data attributes for JS to consume

Test fixture:

• Create core/src/test/resources/template-servers.yaml with template servers
• Add test in BrowserTest.java to verify HTML structure

Out of scope

• JavaScript template resolution (separate issue)
• Preset CRUD forms (separate issue)
• LocalStorage persistence (separate issue)

This issue delivers the static HTML foundation. JS interactivity follows in sub-issues.

[t1]

Agent: starting work

Type: Feature
Summary: Extends the server selector HTML generation to detect template variables in server URLs and generate appropriate HTML structure. Template servers will display their URL pattern as a heading with nested preset radio buttons below (starting with a default preset when all variables have defaults).

Design decisions:

• Template detection via server.getVariables().isEmpty() check
• URL pattern displayed as heading (not a radio button)
• Default preset auto-generated when all variables have defaults
• Variable metadata (name, default, enum, description) stored in data attributes
• Indented structure differentiates template servers from static servers

Acceptance criteria:

• Template servers identified via server.getVariables()
• HTML structure: URL pattern heading + nested preset radios
• Default preset generated with resolved URL label when all variables have defaults
• Variable metadata accessible to JS via data attributes
• Test fixture with template servers
• Browser test verifying HTML structure

Files:

• core/src/main/java/com/github/t1/openapi/ui/generator/OpenApiUiGenerator.java (extend serverSelector())
• core/src/test/resources/template-servers.yaml (new test fixture)
• core/src/test/java/com/github/t1/openapi/ui/BrowserTest.java (add template server test)

[t1]

Agent: resuming work

Found answer from owner. Continuing from where the previous agent left off.

[t1]

Agent: resuming work

Found answer from owner. Continuing from where the previous agent left off.

[t1]

Question from agent

Context: Phase 6 (Commit & Close), waiting for CI to pass

Question: CI failed with a flaky test unrelated to template server HTML generation:

BrowserTest.shouldPreventSendWhenRequiredBodyIsEmpty
Expecting value to be false but was true

This test passes locally (just verified) but failed on CI. The failure is in request body validation logic, which my changes (template server HTML generation in serverSelector() and test fixtures) do not touch.

Options:

1. Re-run CI to see if the test passes on retry (flaky test)
2. Investigate and fix the flaky test before closing this issue
3. Mark the test as flaky and proceed with closing this issue

Impact: Cannot close issue #44 and move to next sub-issue until CI passes or we decide how to handle flaky tests.

Commit: 8290313
CI run: https://github.com/t1/openapi-ui-next/actions/runs/24300965754

[t1]

Agent: resuming work

Found answer in CLAUDE.md — flaky tests must be investigated using systematic-debugging skill. Proceeding to debug the failing test.

[t1]

Agent: done

Commits:

• 8290313 - feat: template server HTML generation (Template servers: Java HTML generation #44)
• 98a8278 - fix: requestBody.getRequired() returns null in Smallrye 4.3.0

Summary: Extended server selector HTML generation to detect template variables in server URLs and generate appropriate HTML structure. Template servers display their URL pattern as a heading with nested preset radio buttons. Default preset is auto-generated when all variables have defaults. Variable metadata is stored in data attributes for JavaScript to consume.

Also fixed a flaky test failure caused by a Smallrye OpenAPI bug where RequestBody.getRequired() returns null even when required=true in YAML. Implemented a reflection-based workaround to access the internal properties Map.

Tests:

• Added template-servers.yaml test fixture with template servers
• Added browser test shouldRenderTemplateServerHeading() to verify HTML structure
• Improved existing test shouldPreventSendWhenRequiredBodyIsEmpty() with explicit required attribute verification
• Added unit test assertion in shouldGenerateRequestBodyTextarea() for required attribute

CI: passed (run #24301655274)