fix(vscode): auto-enable multi-language worker for JDBC connector

[Andrew Eldridge (andrew-eldridge)]

Commit Type

• feature - New functionality
• fix - Bug fix
• refactor - Code restructuring without behavior change
• perf - Performance improvement
• docs - Documentation update
• test - Test-related changes
• chore - Maintenance/tooling

Risk Level

• Low - Minor changes, limited scope
• Medium - Moderate changes, some user impact
• High - Major changes, significant user/system impact

What & Why

Fixes #8597. Using the JDBC built-in connector in a local Standard Logic App failed with "JDBC client library is missing" even when the driver JAR (for example, ojdbc8.jar) was correctly placed in lib/builtinOperationSdks/JAR.

The JDBC connector is a Java built-in operation that only runs when the Functions multi-language Java worker is enabled via the app setting AzureWebJobsFeatureFlags=EnableMultiLanguageWorker. The extension only wrote that flag for customCode, rulesEngine, and codeful project types, so a plain codeless Logic App never got it and the Java worker never started locally. This is why it works in the Portal/Kudu, where the runtime is already provisioned, but not in VS Code.

This change makes the tooling self-heal the prerequisite instead of requiring users to discover it by trial and error:

• Auto-enable the worker: on design-time startup, when driver JARs are detected in lib/builtinOperationSdks/JAR, EnableMultiLanguageWorker is merged into local.settings.json. The merge preserves existing flags and is idempotent, so it does not clobber user values.
• JDK guidance: the JDBC connector also needs a locally installed JDK. When driver JARs are present but no Java runtime is found on PATH, a non-blocking warning with a "Learn more" link to the connector docs is shown, so the prerequisite is clear up front.

The JAR-detection, flag-merge, and Java-runtime checks live in app/utils/java/jdbcConnector.ts so they are easy to test and reuse. createLibFolder was also updated to reuse the new folder-name constants with no behavior change.

Impact of Change

• Users: Local JDBC connections now work after dropping the driver JAR into lib/builtinOperationSdks/JAR and reopening the designer, with clear guidance when a JDK is missing. No manual local.settings.json edit is required.
• Developers: Adds app/utils/java/jdbcConnector.ts helpers (hasJdbcDriverJars, mergeMultiLanguageWorkerFlag, isJavaRuntimeInstalled, warnIfJdbcJavaRuntimeMissing) and new builtinOperationSdksFolderName, jarFolderName, and jdbcConnectorDocsUrl constants.
• System: The multi-language worker is only enabled when driver JARs are present, so projects that never use Java are unaffected. Because this ships in the VS Code extension and can update local runtime settings, the PR is classified as Medium risk.

Test Plan

• Unit tests added/updated
• E2E tests added/updated
• Manual testing completed
• Tested in: pnpm run test:extension-unit (jdbcConnector 19 tests, validateProjectArtifacts 56 tests including 4 new tests, CreateLogicAppWorkspace 83 tests) all passing; E2E integration suite type-checks via tsc -p tsconfig.e2e.json; Biome clean; changed files type-check clean.

New coverage:

• app/utils/java/__test__/jdbcConnector.test.ts - JAR detection (casing, empty folder, non-JAR files, missing folder), flag merge (empty, idempotent, preserve, dedupe, whitespace), Java runtime check, and warning flow.
• validateProjectArtifacts.test.ts - self-heal branches (add, merge without clobbering, idempotent, no-op when no JARs).
• test/e2e/integration/jdbcConnectorPrerequisites.test.ts - real on-disk contract for the self-heal.

Contributors

Root cause and prerequisites corroborated by community findings on the issue thread (Matt Milner (@mnmilner)).

Screenshots/Videos

N/A - no visual UI changes.

Closes #8597

[github-actions]

🤖 AI PR Validation Report

PR Review Results

Thank you for your submission! Here's detailed feedback on your PR title and body compliance:

✅ PR Title

• Current: fix(vscode): auto-enable multi-language worker for JDBC connector
• Issue: None — valid fix: prefix with scope, and clearly descriptive of the behavior change.
• Recommendation: No change needed.

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✅ Commit Type

• Exactly one type selected: fix - Bug fix.
• Matches the diff, which repairs the missing EnableMultiLanguageWorker flag for JDBC — a genuine bug fix.

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✅ Risk Level

• Medium selected in the body and the risk:medium label is present — both agree. This matches the advised estimate: the change ships in the VS Code extension (apps/vs-code-designer) and mutates local runtime settings (local.settings.json), which is squarely Medium per the rubric. No security/auth or shared-logic-apps-shared impact that would raise it to High.

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✅ What & Why

• Current: Clear root-cause explanation (Java worker only enabled for customCode/rulesEngine/codeful; plain codeless never got the flag) plus the self-heal approach.
• Issue: None.
• Recommendation: No change needed.

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✅ Impact of Change

• All three audiences addressed (Users, Developers, System) with concrete detail including new helpers and constants.
• Recommendation:
  • Users: Well covered — local JDBC works after dropping the JAR; JDK guidance shown.
  • Developers: Well covered — new jdbcConnector.ts helpers and constants listed.
  • System: Well covered — worker only enabled when JARs present.

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✅ Test Plan

• Unit tests added/updated (jdbcConnector.test.ts, projectFilesConsistency.test.ts, localSettings.test.ts) and E2E tests added (jdbcConnectorPrerequisites.test.ts), all confirmed in the diff. Passes the CHECK TESTS rule comfortably.

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⚠️ Contributors

• Credited Matt Milner (@mnmilner) for community findings. Not blank — no action required.

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✅ Screenshots/Videos

• Diff touches only apps/vs-code-designer (backend/tooling logic, no designer-ui/designer/vs-code-react UI components). No visual change, so screenshots are not required. N/A is appropriate.

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Summary Table

Section	Status	Recommendation
Title	✅	No change needed
Commit Type	✅	No change needed
Risk Level	✅	Medium is correct (extension + local settings)
What & Why	✅	No change needed
Impact of Change	✅	No change needed
Test Plan	✅	No change needed
Contributors	⚠️	Optional — already credited
Screenshots/Videos	✅	N/A is appropriate

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All required checks pass. This PR is compliant with the team template and is cleared to merge. Nice work on the thorough root-cause writeup and test coverage.

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Powered by: Copilot CLI (claude-opus-4.8) | Last updated: Thu, 13 Aug 2026 19:31:30 GMT

[github-actions]

📊 Coverage Check

🎉 All changed files have adequate test coverage!

[Copilot]

Pull request overview

Fixes local JDBC connector startup by enabling the Java worker when driver JARs are detected and warning when Java is unavailable.

Changes:

• Detects JDBC drivers and merges the multi-language worker flag.
• Adds Java prerequisite guidance.
• Adds unit and integration coverage.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
jdbcConnectorPrerequisites.test.ts	Adds filesystem integration tests.
constants.ts	Adds JDBC paths and documentation URL.
jdbcConnector.ts	Adds JAR and Java detection.
jdbcConnector.test.ts	Tests JDBC utilities and warning flow.
startDesignTimeApi.ts	Runs the Java prerequisite check.
projectFilesConsistency.ts	Repairs feature flags when JDBC drivers exist.
localSettings.ts	Generates JDBC-aware settings.
localSettings.test.ts	Tests JDBC-aware generation.
projectFilesConsistency.test.ts	Tests settings self-healing.
CreateLogicAppWorkspace.ts	Reuses folder constants.

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