Add new diagnostic env var names matching renamed CLI options

[Amaury Levé (Evangelink)]

Fixes#7159.

The CLI options were renamed in #6165:

• --diagnostic-output-fileprefix → --diagnostic-file-prefix
• --diagnostic-filelogger-synchronouswrite → --diagnostic-synchronous-write

but the matching environment variables kept their old names, so the option and env var names are no longer consistent:

• TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX
• TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE

Renaming the env vars outright would be a breaking change, so this PR instead adds new env var names that align with the new CLI option names, while keeping the legacy names working.

Changes

• EnvironmentVariableConstants.cs: added TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE. Documented the legacy constants as deprecated (kept for back-compat, to be removed in the next breaking-change version).
• TestApplication.cs: when reading the diagnostic file prefix / synchronous write env vars, the new name is read first and the legacy name is used as a fallback. This means existing users on the legacy names are not affected, and the new names take precedence when both are set.
• DiagnosticTests.cs: kept the existing acceptance tests covering the legacy names so we don't lose back-compat coverage, and added three new tests:
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_SynchronousWrite_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewNameTakesPrecedence

No public API surface area was added — EnvironmentVariableConstants is internal (and is source-linked into the acceptance test project, so the new constants are automatically visible to tests).

The documentation update referenced in the issue lives in dotnet/docs and is tracked separately per the issue comment.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds new environment variable names for diagnostic settings to match the renamed CLI options, while preserving the legacy env var names for backward compatibility.

Changes:

• Introduces TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE constants (legacy constants noted as deprecated).
• Updates diagnostic env var reading logic to prefer the new names and fall back to legacy names.
• Adds acceptance tests verifying the new env var names and precedence behavior.

Show a summary per file

File	Description
test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DiagnosticTests.cs	Adds new acceptance tests for the new env var names and precedence behavior.
src/Platform/Microsoft.Testing.Platform/Helpers/EnvironmentVariableConstants.cs	Adds new env var constants and annotates legacy constants with deprecation comments.
src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs	Prefers new env vars for diagnostic prefix / synchronous write with legacy fallback.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Added a follow-up commit that emits a deprecation warning when the legacy diagnostic env vars are set.

• New localized resource DeprecatedEnvironmentVariableWarning in PlatformResources.resx (XLF files regenerated via UpdateXlf):

  Warning: The environment variable '{0}' is deprecated and will be removed in a future major version. Use '{1}' instead.

• TestApplication.CreateFileLoggerIfDiagnosticIsEnabled writes the warning to the existing SystemConsole whenever TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX or TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE is set — even when the new name is also set and wins. This guarantees migration signal regardless of precedence.
• Updated the acceptance tests:
  • Legacy-name tests assert the warning is emitted.
  • New-name tests assert the warning is not emitted.
  • ...NewNameTakesPrecedence asserts the warning still fires when both env vars are set.

[Amaury Levé (Evangelink)]

Expert Review — PR #8388

#	Dimension	Verdict
13	Test Completeness & Coverage	🟢 1 NIT

✅ 20/21 dimensions clean.

• Test coverage: missing SynchronousWrite_NewNameTakesPrecedence test (symmetric to the existing CustomPrefix_NewNameTakesPrecedence)

---

Summary

The change is correct and well-structured. The fallback logic in TestApplication.cs correctly prefers the new env var names and falls back to the legacy names when the new ones are absent or empty. The EnvironmentVariableConstants.cs constants are internal, so no PublicAPI.Unshipped.txt update is needed and no [Obsolete] is required by policy (though it would be a helpful internal signal — optional).

The three new acceptance tests cover the happy paths for both new names and the precedence case for the file-prefix pair. The only gap is the missing symmetric precedence test for the synchronous-write pair (filed as a NIT inline comment above).

No blocking or major issues found.

Generated by Expert Code Review (on open) for issue #8388 · ● 5.1M

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Amaury Levé (Evangelink)]

Fixes#7159.

The CLI options were renamed in #6165:

• --diagnostic-output-fileprefix → --diagnostic-file-prefix
• --diagnostic-filelogger-synchronouswrite → --diagnostic-synchronous-write

but the matching environment variables kept their old names, so the option and env var names are no longer consistent:

• TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX
• TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE

Renaming the env vars outright would be a breaking change, so this PR instead adds new env var names that align with the new CLI option names, while keeping the legacy names working.

Changes

• EnvironmentVariableConstants.cs: added TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE. Documented the legacy constants as deprecated (kept for back-compat, to be removed in the next breaking-change version).
• TestApplication.cs: when reading the diagnostic file prefix / synchronous write env vars, the new name is read first and the legacy name is used as a fallback. This means existing users on the legacy names are not affected, and the new names take precedence when both are set.
• DiagnosticTests.cs: kept the existing acceptance tests covering the legacy names so we don't lose back-compat coverage, and added three new tests:
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_SynchronousWrite_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewNameTakesPrecedence

No public API surface area was added — EnvironmentVariableConstants is internal (and is source-linked into the acceptance test project, so the new constants are automatically visible to tests).

The documentation update referenced in the issue lives in dotnet/docs and is tracked separately per the issue comment.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds new environment variable names for diagnostic settings to match the renamed CLI options, while preserving the legacy env var names for backward compatibility.

Changes:

• Introduces TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE constants (legacy constants noted as deprecated).
• Updates diagnostic env var reading logic to prefer the new names and fall back to legacy names.
• Adds acceptance tests verifying the new env var names and precedence behavior.

Show a summary per file

File	Description
test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DiagnosticTests.cs	Adds new acceptance tests for the new env var names and precedence behavior.
src/Platform/Microsoft.Testing.Platform/Helpers/EnvironmentVariableConstants.cs	Adds new env var constants and annotates legacy constants with deprecation comments.
src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs	Prefers new env vars for diagnostic prefix / synchronous write with legacy fallback.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Added a follow-up commit that emits a deprecation warning when the legacy diagnostic env vars are set.

• New localized resource DeprecatedEnvironmentVariableWarning in PlatformResources.resx (XLF files regenerated via UpdateXlf):

  Warning: The environment variable '{0}' is deprecated and will be removed in a future major version. Use '{1}' instead.

• TestApplication.CreateFileLoggerIfDiagnosticIsEnabled writes the warning to the existing SystemConsole whenever TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX or TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE is set — even when the new name is also set and wins. This guarantees migration signal regardless of precedence.
• Updated the acceptance tests:
  • Legacy-name tests assert the warning is emitted.
  • New-name tests assert the warning is not emitted.
  • ...NewNameTakesPrecedence asserts the warning still fires when both env vars are set.

[Amaury Levé (Evangelink)]

Expert Review — PR #8388

#	Dimension	Verdict
13	Test Completeness & Coverage	🟢 1 NIT

✅ 20/21 dimensions clean.

• Test coverage: missing SynchronousWrite_NewNameTakesPrecedence test (symmetric to the existing CustomPrefix_NewNameTakesPrecedence)

---

Summary

The change is correct and well-structured. The fallback logic in TestApplication.cs correctly prefers the new env var names and falls back to the legacy names when the new ones are absent or empty. The EnvironmentVariableConstants.cs constants are internal, so no PublicAPI.Unshipped.txt update is needed and no [Obsolete] is required by policy (though it would be a helpful internal signal — optional).

The three new acceptance tests cover the happy paths for both new names and the precedence case for the file-prefix pair. The only gap is the missing symmetric precedence test for the synchronous-write pair (filed as a NIT inline comment above).

No blocking or major issues found.

Generated by Expert Code Review (on open) for issue #8388 · ● 5.1M

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Amaury Levé (Evangelink)]

Fixes#7159.

The CLI options were renamed in #6165:

• --diagnostic-output-fileprefix → --diagnostic-file-prefix
• --diagnostic-filelogger-synchronouswrite → --diagnostic-synchronous-write

but the matching environment variables kept their old names, so the option and env var names are no longer consistent:

• TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX
• TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE

Renaming the env vars outright would be a breaking change, so this PR instead adds new env var names that align with the new CLI option names, while keeping the legacy names working.

Changes

• EnvironmentVariableConstants.cs: added TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE. Documented the legacy constants as deprecated (kept for back-compat, to be removed in the next breaking-change version).
• TestApplication.cs: when reading the diagnostic file prefix / synchronous write env vars, the new name is read first and the legacy name is used as a fallback. This means existing users on the legacy names are not affected, and the new names take precedence when both are set.
• DiagnosticTests.cs: kept the existing acceptance tests covering the legacy names so we don't lose back-compat coverage, and added three new tests:
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_SynchronousWrite_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewNameTakesPrecedence

No public API surface area was added — EnvironmentVariableConstants is internal (and is source-linked into the acceptance test project, so the new constants are automatically visible to tests).

The documentation update referenced in the issue lives in dotnet/docs and is tracked separately per the issue comment.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds new environment variable names for diagnostic settings to match the renamed CLI options, while preserving the legacy env var names for backward compatibility.

Changes:

• Introduces TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE constants (legacy constants noted as deprecated).
• Updates diagnostic env var reading logic to prefer the new names and fall back to legacy names.
• Adds acceptance tests verifying the new env var names and precedence behavior.

Show a summary per file

File	Description
test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DiagnosticTests.cs	Adds new acceptance tests for the new env var names and precedence behavior.
src/Platform/Microsoft.Testing.Platform/Helpers/EnvironmentVariableConstants.cs	Adds new env var constants and annotates legacy constants with deprecation comments.
src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs	Prefers new env vars for diagnostic prefix / synchronous write with legacy fallback.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Added a follow-up commit that emits a deprecation warning when the legacy diagnostic env vars are set.

• New localized resource DeprecatedEnvironmentVariableWarning in PlatformResources.resx (XLF files regenerated via UpdateXlf):

  Warning: The environment variable '{0}' is deprecated and will be removed in a future major version. Use '{1}' instead.

• TestApplication.CreateFileLoggerIfDiagnosticIsEnabled writes the warning to the existing SystemConsole whenever TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX or TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE is set — even when the new name is also set and wins. This guarantees migration signal regardless of precedence.
• Updated the acceptance tests:
  • Legacy-name tests assert the warning is emitted.
  • New-name tests assert the warning is not emitted.
  • ...NewNameTakesPrecedence asserts the warning still fires when both env vars are set.

[Amaury Levé (Evangelink)]

Expert Review — PR #8388

#	Dimension	Verdict
13	Test Completeness & Coverage	🟢 1 NIT

✅ 20/21 dimensions clean.

• Test coverage: missing SynchronousWrite_NewNameTakesPrecedence test (symmetric to the existing CustomPrefix_NewNameTakesPrecedence)

---

Summary

The change is correct and well-structured. The fallback logic in TestApplication.cs correctly prefers the new env var names and falls back to the legacy names when the new ones are absent or empty. The EnvironmentVariableConstants.cs constants are internal, so no PublicAPI.Unshipped.txt update is needed and no [Obsolete] is required by policy (though it would be a helpful internal signal — optional).

The three new acceptance tests cover the happy paths for both new names and the precedence case for the file-prefix pair. The only gap is the missing symmetric precedence test for the synchronous-write pair (filed as a NIT inline comment above).

No blocking or major issues found.

Generated by Expert Code Review (on open) for issue #8388 · ● 5.1M

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Amaury Levé (Evangelink)]

Fixes#7159.

The CLI options were renamed in #6165:

• --diagnostic-output-fileprefix → --diagnostic-file-prefix
• --diagnostic-filelogger-synchronouswrite → --diagnostic-synchronous-write

but the matching environment variables kept their old names, so the option and env var names are no longer consistent:

• TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX
• TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE

Renaming the env vars outright would be a breaking change, so this PR instead adds new env var names that align with the new CLI option names, while keeping the legacy names working.

Changes

• EnvironmentVariableConstants.cs: added TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE. Documented the legacy constants as deprecated (kept for back-compat, to be removed in the next breaking-change version).
• TestApplication.cs: when reading the diagnostic file prefix / synchronous write env vars, the new name is read first and the legacy name is used as a fallback. This means existing users on the legacy names are not affected, and the new names take precedence when both are set.
• DiagnosticTests.cs: kept the existing acceptance tests covering the legacy names so we don't lose back-compat coverage, and added three new tests:
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_SynchronousWrite_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewNameTakesPrecedence

No public API surface area was added — EnvironmentVariableConstants is internal (and is source-linked into the acceptance test project, so the new constants are automatically visible to tests).

The documentation update referenced in the issue lives in dotnet/docs and is tracked separately per the issue comment.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds new environment variable names for diagnostic settings to match the renamed CLI options, while preserving the legacy env var names for backward compatibility.

Changes:

• Introduces TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE constants (legacy constants noted as deprecated).
• Updates diagnostic env var reading logic to prefer the new names and fall back to legacy names.
• Adds acceptance tests verifying the new env var names and precedence behavior.

Show a summary per file

File	Description
test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DiagnosticTests.cs	Adds new acceptance tests for the new env var names and precedence behavior.
src/Platform/Microsoft.Testing.Platform/Helpers/EnvironmentVariableConstants.cs	Adds new env var constants and annotates legacy constants with deprecation comments.
src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs	Prefers new env vars for diagnostic prefix / synchronous write with legacy fallback.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Added a follow-up commit that emits a deprecation warning when the legacy diagnostic env vars are set.

• New localized resource DeprecatedEnvironmentVariableWarning in PlatformResources.resx (XLF files regenerated via UpdateXlf):

  Warning: The environment variable '{0}' is deprecated and will be removed in a future major version. Use '{1}' instead.

• TestApplication.CreateFileLoggerIfDiagnosticIsEnabled writes the warning to the existing SystemConsole whenever TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX or TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE is set — even when the new name is also set and wins. This guarantees migration signal regardless of precedence.
• Updated the acceptance tests:
  • Legacy-name tests assert the warning is emitted.
  • New-name tests assert the warning is not emitted.
  • ...NewNameTakesPrecedence asserts the warning still fires when both env vars are set.

[Amaury Levé (Evangelink)]

Expert Review — PR #8388

#	Dimension	Verdict
13	Test Completeness & Coverage	🟢 1 NIT

✅ 20/21 dimensions clean.

• Test coverage: missing SynchronousWrite_NewNameTakesPrecedence test (symmetric to the existing CustomPrefix_NewNameTakesPrecedence)

---

Summary

The change is correct and well-structured. The fallback logic in TestApplication.cs correctly prefers the new env var names and falls back to the legacy names when the new ones are absent or empty. The EnvironmentVariableConstants.cs constants are internal, so no PublicAPI.Unshipped.txt update is needed and no [Obsolete] is required by policy (though it would be a helpful internal signal — optional).

The three new acceptance tests cover the happy paths for both new names and the precedence case for the file-prefix pair. The only gap is the missing symmetric precedence test for the synchronous-write pair (filed as a NIT inline comment above).

No blocking or major issues found.

Generated by Expert Code Review (on open) for issue #8388 · ● 5.1M

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Amaury Levé (Evangelink)]

Fixes#7159.

The CLI options were renamed in #6165:

• --diagnostic-output-fileprefix → --diagnostic-file-prefix
• --diagnostic-filelogger-synchronouswrite → --diagnostic-synchronous-write

but the matching environment variables kept their old names, so the option and env var names are no longer consistent:

• TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX
• TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE

Renaming the env vars outright would be a breaking change, so this PR instead adds new env var names that align with the new CLI option names, while keeping the legacy names working.

Changes

• EnvironmentVariableConstants.cs: added TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE. Documented the legacy constants as deprecated (kept for back-compat, to be removed in the next breaking-change version).
• TestApplication.cs: when reading the diagnostic file prefix / synchronous write env vars, the new name is read first and the legacy name is used as a fallback. This means existing users on the legacy names are not affected, and the new names take precedence when both are set.
• DiagnosticTests.cs: kept the existing acceptance tests covering the legacy names so we don't lose back-compat coverage, and added three new tests:
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_SynchronousWrite_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewNameTakesPrecedence

No public API surface area was added — EnvironmentVariableConstants is internal (and is source-linked into the acceptance test project, so the new constants are automatically visible to tests).

The documentation update referenced in the issue lives in dotnet/docs and is tracked separately per the issue comment.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds new environment variable names for diagnostic settings to match the renamed CLI options, while preserving the legacy env var names for backward compatibility.

Changes:

• Introduces TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE constants (legacy constants noted as deprecated).
• Updates diagnostic env var reading logic to prefer the new names and fall back to legacy names.
• Adds acceptance tests verifying the new env var names and precedence behavior.

Show a summary per file

File	Description
test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DiagnosticTests.cs	Adds new acceptance tests for the new env var names and precedence behavior.
src/Platform/Microsoft.Testing.Platform/Helpers/EnvironmentVariableConstants.cs	Adds new env var constants and annotates legacy constants with deprecation comments.
src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs	Prefers new env vars for diagnostic prefix / synchronous write with legacy fallback.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Added a follow-up commit that emits a deprecation warning when the legacy diagnostic env vars are set.

• New localized resource DeprecatedEnvironmentVariableWarning in PlatformResources.resx (XLF files regenerated via UpdateXlf):

  Warning: The environment variable '{0}' is deprecated and will be removed in a future major version. Use '{1}' instead.

• TestApplication.CreateFileLoggerIfDiagnosticIsEnabled writes the warning to the existing SystemConsole whenever TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX or TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE is set — even when the new name is also set and wins. This guarantees migration signal regardless of precedence.
• Updated the acceptance tests:
  • Legacy-name tests assert the warning is emitted.
  • New-name tests assert the warning is not emitted.
  • ...NewNameTakesPrecedence asserts the warning still fires when both env vars are set.

[Amaury Levé (Evangelink)]

Expert Review — PR #8388

#	Dimension	Verdict
13	Test Completeness & Coverage	🟢 1 NIT

✅ 20/21 dimensions clean.

• Test coverage: missing SynchronousWrite_NewNameTakesPrecedence test (symmetric to the existing CustomPrefix_NewNameTakesPrecedence)

---

Summary

The change is correct and well-structured. The fallback logic in TestApplication.cs correctly prefers the new env var names and falls back to the legacy names when the new ones are absent or empty. The EnvironmentVariableConstants.cs constants are internal, so no PublicAPI.Unshipped.txt update is needed and no [Obsolete] is required by policy (though it would be a helpful internal signal — optional).

The three new acceptance tests cover the happy paths for both new names and the precedence case for the file-prefix pair. The only gap is the missing symmetric precedence test for the synchronous-write pair (filed as a NIT inline comment above).

No blocking or major issues found.

Generated by Expert Code Review (on open) for issue #8388 · ● 5.1M

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Amaury Levé (Evangelink)]

Fixes#7159.

The CLI options were renamed in #6165:

• --diagnostic-output-fileprefix → --diagnostic-file-prefix
• --diagnostic-filelogger-synchronouswrite → --diagnostic-synchronous-write

but the matching environment variables kept their old names, so the option and env var names are no longer consistent:

• TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX
• TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE

Renaming the env vars outright would be a breaking change, so this PR instead adds new env var names that align with the new CLI option names, while keeping the legacy names working.

Changes

• EnvironmentVariableConstants.cs: added TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE. Documented the legacy constants as deprecated (kept for back-compat, to be removed in the next breaking-change version).
• TestApplication.cs: when reading the diagnostic file prefix / synchronous write env vars, the new name is read first and the legacy name is used as a fallback. This means existing users on the legacy names are not affected, and the new names take precedence when both are set.
• DiagnosticTests.cs: kept the existing acceptance tests covering the legacy names so we don't lose back-compat coverage, and added three new tests:
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_SynchronousWrite_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewNameTakesPrecedence

No public API surface area was added — EnvironmentVariableConstants is internal (and is source-linked into the acceptance test project, so the new constants are automatically visible to tests).

The documentation update referenced in the issue lives in dotnet/docs and is tracked separately per the issue comment.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds new environment variable names for diagnostic settings to match the renamed CLI options, while preserving the legacy env var names for backward compatibility.

Changes:

• Introduces TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE constants (legacy constants noted as deprecated).
• Updates diagnostic env var reading logic to prefer the new names and fall back to legacy names.
• Adds acceptance tests verifying the new env var names and precedence behavior.

Show a summary per file

File	Description
test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DiagnosticTests.cs	Adds new acceptance tests for the new env var names and precedence behavior.
src/Platform/Microsoft.Testing.Platform/Helpers/EnvironmentVariableConstants.cs	Adds new env var constants and annotates legacy constants with deprecation comments.
src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs	Prefers new env vars for diagnostic prefix / synchronous write with legacy fallback.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Added a follow-up commit that emits a deprecation warning when the legacy diagnostic env vars are set.

• New localized resource DeprecatedEnvironmentVariableWarning in PlatformResources.resx (XLF files regenerated via UpdateXlf):

  Warning: The environment variable '{0}' is deprecated and will be removed in a future major version. Use '{1}' instead.

• TestApplication.CreateFileLoggerIfDiagnosticIsEnabled writes the warning to the existing SystemConsole whenever TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX or TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE is set — even when the new name is also set and wins. This guarantees migration signal regardless of precedence.
• Updated the acceptance tests:
  • Legacy-name tests assert the warning is emitted.
  • New-name tests assert the warning is not emitted.
  • ...NewNameTakesPrecedence asserts the warning still fires when both env vars are set.

[Amaury Levé (Evangelink)]

Expert Review — PR #8388

#	Dimension	Verdict
13	Test Completeness & Coverage	🟢 1 NIT

✅ 20/21 dimensions clean.

• Test coverage: missing SynchronousWrite_NewNameTakesPrecedence test (symmetric to the existing CustomPrefix_NewNameTakesPrecedence)

---

Summary

The change is correct and well-structured. The fallback logic in TestApplication.cs correctly prefers the new env var names and falls back to the legacy names when the new ones are absent or empty. The EnvironmentVariableConstants.cs constants are internal, so no PublicAPI.Unshipped.txt update is needed and no [Obsolete] is required by policy (though it would be a helpful internal signal — optional).

The three new acceptance tests cover the happy paths for both new names and the precedence case for the file-prefix pair. The only gap is the missing symmetric precedence test for the synchronous-write pair (filed as a NIT inline comment above).

No blocking or major issues found.

Generated by Expert Code Review (on open) for issue #8388 · ● 5.1M

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Amaury Levé (Evangelink)]

Fixes#7159.

The CLI options were renamed in #6165:

• --diagnostic-output-fileprefix → --diagnostic-file-prefix
• --diagnostic-filelogger-synchronouswrite → --diagnostic-synchronous-write

but the matching environment variables kept their old names, so the option and env var names are no longer consistent:

• TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX
• TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE

Renaming the env vars outright would be a breaking change, so this PR instead adds new env var names that align with the new CLI option names, while keeping the legacy names working.

Changes

• EnvironmentVariableConstants.cs: added TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE. Documented the legacy constants as deprecated (kept for back-compat, to be removed in the next breaking-change version).
• TestApplication.cs: when reading the diagnostic file prefix / synchronous write env vars, the new name is read first and the legacy name is used as a fallback. This means existing users on the legacy names are not affected, and the new names take precedence when both are set.
• DiagnosticTests.cs: kept the existing acceptance tests covering the legacy names so we don't lose back-compat coverage, and added three new tests:
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_SynchronousWrite_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewNameTakesPrecedence

No public API surface area was added — EnvironmentVariableConstants is internal (and is source-linked into the acceptance test project, so the new constants are automatically visible to tests).

The documentation update referenced in the issue lives in dotnet/docs and is tracked separately per the issue comment.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds new environment variable names for diagnostic settings to match the renamed CLI options, while preserving the legacy env var names for backward compatibility.

Changes:

• Introduces TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE constants (legacy constants noted as deprecated).
• Updates diagnostic env var reading logic to prefer the new names and fall back to legacy names.
• Adds acceptance tests verifying the new env var names and precedence behavior.

Show a summary per file

File	Description
test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DiagnosticTests.cs	Adds new acceptance tests for the new env var names and precedence behavior.
src/Platform/Microsoft.Testing.Platform/Helpers/EnvironmentVariableConstants.cs	Adds new env var constants and annotates legacy constants with deprecation comments.
src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs	Prefers new env vars for diagnostic prefix / synchronous write with legacy fallback.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Added a follow-up commit that emits a deprecation warning when the legacy diagnostic env vars are set.

• New localized resource DeprecatedEnvironmentVariableWarning in PlatformResources.resx (XLF files regenerated via UpdateXlf):

  Warning: The environment variable '{0}' is deprecated and will be removed in a future major version. Use '{1}' instead.

• TestApplication.CreateFileLoggerIfDiagnosticIsEnabled writes the warning to the existing SystemConsole whenever TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX or TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE is set — even when the new name is also set and wins. This guarantees migration signal regardless of precedence.
• Updated the acceptance tests:
  • Legacy-name tests assert the warning is emitted.
  • New-name tests assert the warning is not emitted.
  • ...NewNameTakesPrecedence asserts the warning still fires when both env vars are set.

[Amaury Levé (Evangelink)]

Expert Review — PR #8388

#	Dimension	Verdict
13	Test Completeness & Coverage	🟢 1 NIT

✅ 20/21 dimensions clean.

• Test coverage: missing SynchronousWrite_NewNameTakesPrecedence test (symmetric to the existing CustomPrefix_NewNameTakesPrecedence)

---

Summary

The change is correct and well-structured. The fallback logic in TestApplication.cs correctly prefers the new env var names and falls back to the legacy names when the new ones are absent or empty. The EnvironmentVariableConstants.cs constants are internal, so no PublicAPI.Unshipped.txt update is needed and no [Obsolete] is required by policy (though it would be a helpful internal signal — optional).

The three new acceptance tests cover the happy paths for both new names and the precedence case for the file-prefix pair. The only gap is the missing symmetric precedence test for the synchronous-write pair (filed as a NIT inline comment above).

No blocking or major issues found.

Generated by Expert Code Review (on open) for issue #8388 · ● 5.1M

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.

[Amaury Levé (Evangelink)]

Fixes#7159.

The CLI options were renamed in #6165:

• --diagnostic-output-fileprefix → --diagnostic-file-prefix
• --diagnostic-filelogger-synchronouswrite → --diagnostic-synchronous-write

but the matching environment variables kept their old names, so the option and env var names are no longer consistent:

• TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX
• TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE

Renaming the env vars outright would be a breaking change, so this PR instead adds new env var names that align with the new CLI option names, while keeping the legacy names working.

Changes

• EnvironmentVariableConstants.cs: added TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE. Documented the legacy constants as deprecated (kept for back-compat, to be removed in the next breaking-change version).
• TestApplication.cs: when reading the diagnostic file prefix / synchronous write env vars, the new name is read first and the legacy name is used as a fallback. This means existing users on the legacy names are not affected, and the new names take precedence when both are set.
• DiagnosticTests.cs: kept the existing acceptance tests covering the legacy names so we don't lose back-compat coverage, and added three new tests:
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_SynchronousWrite_NewName_Succeeded
  • Diag_EnableWithEnvironmentVariables_CustomPrefix_NewNameTakesPrecedence

No public API surface area was added — EnvironmentVariableConstants is internal (and is source-linked into the acceptance test project, so the new constants are automatically visible to tests).

The documentation update referenced in the issue lives in dotnet/docs and is tracked separately per the issue comment.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds new environment variable names for diagnostic settings to match the renamed CLI options, while preserving the legacy env var names for backward compatibility.

Changes:

• Introduces TESTINGPLATFORM_DIAGNOSTIC_FILE_PREFIX and TESTINGPLATFORM_DIAGNOSTIC_SYNCHRONOUS_WRITE constants (legacy constants noted as deprecated).
• Updates diagnostic env var reading logic to prefer the new names and fall back to legacy names.
• Adds acceptance tests verifying the new env var names and precedence behavior.

Show a summary per file

File	Description
test/IntegrationTests/Microsoft.Testing.Platform.Acceptance.IntegrationTests/DiagnosticTests.cs	Adds new acceptance tests for the new env var names and precedence behavior.
src/Platform/Microsoft.Testing.Platform/Helpers/EnvironmentVariableConstants.cs	Adds new env var constants and annotates legacy constants with deprecation comments.
src/Platform/Microsoft.Testing.Platform/Builder/TestApplication.cs	Prefers new env vars for diagnostic prefix / synchronous write with legacy fallback.

Copilot's findings

• Files reviewed: 3/3 changed files
• Comments generated: 2

[Amaury Levé (Evangelink)]

Added a follow-up commit that emits a deprecation warning when the legacy diagnostic env vars are set.

• New localized resource DeprecatedEnvironmentVariableWarning in PlatformResources.resx (XLF files regenerated via UpdateXlf):

  Warning: The environment variable '{0}' is deprecated and will be removed in a future major version. Use '{1}' instead.

• TestApplication.CreateFileLoggerIfDiagnosticIsEnabled writes the warning to the existing SystemConsole whenever TESTINGPLATFORM_DIAGNOSTIC_OUTPUT_FILEPREFIX or TESTINGPLATFORM_DIAGNOSTIC_FILELOGGER_SYNCHRONOUSWRITE is set — even when the new name is also set and wins. This guarantees migration signal regardless of precedence.
• Updated the acceptance tests:
  • Legacy-name tests assert the warning is emitted.
  • New-name tests assert the warning is not emitted.
  • ...NewNameTakesPrecedence asserts the warning still fires when both env vars are set.

[Amaury Levé (Evangelink)]

Expert Review — PR #8388

#	Dimension	Verdict
13	Test Completeness & Coverage	🟢 1 NIT

✅ 20/21 dimensions clean.

• Test coverage: missing SynchronousWrite_NewNameTakesPrecedence test (symmetric to the existing CustomPrefix_NewNameTakesPrecedence)

---

Summary

The change is correct and well-structured. The fallback logic in TestApplication.cs correctly prefers the new env var names and falls back to the legacy names when the new ones are absent or empty. The EnvironmentVariableConstants.cs constants are internal, so no PublicAPI.Unshipped.txt update is needed and no [Obsolete] is required by policy (though it would be a helpful internal signal — optional).

The three new acceptance tests cover the happy paths for both new names and the precedence case for the file-prefix pair. The only gap is the missing symmetric precedence test for the synchronous-write pair (filed as a NIT inline comment above).

No blocking or major issues found.

Generated by Expert Code Review (on open) for issue #8388 · ● 5.1M

[Copilot]

Copilot encountered an error and was unable to review this pull request. You can try again by re-requesting a review.