FileConfigurationProvider: Handle and forward IO exceptions to OnLoadException by mrek-msft · Pull Request #126093 · dotnet/runtime

mrek-msft · 2026-03-25T15:31:05Z

Current behavior of FileConfigurationProvider on various types of failures at various times:

	First Load	OnChange Reload
data parsing failure	`OnLoadException` callback is called `AddJsonFile` throws	`OnLoadException` callback is called program continues no reload happen
IO failure on file open	`AddJsonFile` throws	Silent program continues no reload happen possibly raises `UnobservedTaskException` later

This PR unifies it in a way that both types of failure behave same as data parsing failure.

This brings some behavioral changes

OnLoadException callback is newly triggered if IO error happen on both types of events (first load, reload)
UnobservedTaskException can no longer be observed in scenario when user registers OnLoadException callback. It can however happen when no callback is registered, so XML comment on OnLoadException was updated.
OnLoadException callbacks now receives not only InvalidDataException, but also IOException (or any other exception which (possibly custom) implementation of IFileProvider can throw). If user cast to InvalidDataException, he may miss other exceptions or get cast exceptions.

Based on follow up Copilot code reviews, I did few more behavior changes at edge cases, they do not relate directly to issue and can be reverted independently if not desired.

OnReload() now fires only when Data actually changed. Previously on first load, if a parse or IO error occurred and OnLoadException set Ignore = true, OnReload() was fired unconditionally even though Data was never modified. The new code fires OnReload() only when Data was successfully loaded or explicitly cleared (e.g., on reload or optional missing file). For consecutive reloads with parse errors, Data is cleared and OnReload() still fires. This change is independent on original fix and can be reverted independently if not desirable.

Fix #113964

Copilot

Pull request overview

Unifies FileConfigurationProvider failure handling so IO failures during file open are handled the same way as parsing failures with respect to OnLoadException (including on reload-on-change), preventing unobserved/unhandled exceptions like the one reported in #113964.

Changes:

Moves stream opening (OpenRead) inside the exception-handling region so IO errors are routed through HandleException/OnLoadException.
Adds an inner try/catch to wrap exceptions thrown by Load(stream) in an InvalidDataException with the standard “Failed to load…” message.
Adjusts the outer catch to forward the exception through HandleException (enabling ignore behavior on reload).

...libraries/Microsoft.Extensions.Configuration.FileExtensions/src/FileConfigurationProvider.cs

Copilot

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 5 comments.

src/libraries/Microsoft.Extensions.Configuration/tests/FunctionalTests/ConfigurationTests.cs

src/libraries/Microsoft.Extensions.Configuration/tests/FunctionalTests/DisposableFileSystem.cs

...libraries/Microsoft.Extensions.Configuration.FileExtensions/src/FileConfigurationProvider.cs

src/libraries/Microsoft.Extensions.Configuration/tests/FunctionalTests/ConfigurationTests.cs

dotnet-policy-service · 2026-03-26T16:23:35Z

Tagging subscribers to this area: @dotnet/area-extensions-filesystem
See info in area-owners.md if you want to be subscribed.

… file path formatting logic.

Copilot

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

src/libraries/Microsoft.Extensions.Configuration/tests/FunctionalTests/ConfigurationTests.cs

src/libraries/Microsoft.Extensions.Configuration/tests/FunctionalTests/DisposableFileSystem.cs

...libraries/Microsoft.Extensions.Configuration.FileExtensions/src/FileConfigurationProvider.cs

svick · 2026-04-02T10:35:52Z

Nit: the documentation of FileLoadExceptionContext.Exception says:

Gets or sets the exception that occurred in Load.

Since it can now contain exceptions that weren't literally thrown from the Load method, I would change it to something like:

Gets or sets the exception that occurred during file loading.

… review

mrek-msft · 2026-04-02T11:14:28Z

Nit: the documentation of FileLoadExceptionContext.Exception says:

Gets or sets the exception that occurred in Load.

Since it can now contain exceptions that weren't literally thrown from the Load method, I would change it to something like:

Gets or sets the exception that occurred during file loading.

I updated it and agree that comment is better, but note that even after changes, all exceptions come from Load, it is just likely different Load then comment mentioned.

rosebyte

I like the direction of the PR, only left couple comments.

mrek-msft · 2026-04-07T11:46:15Z

@copilot please invoke the code-review skill and post the analysis/results as a comment on this PR.

Copilot

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.

… forwarding to OnLoadException Agent-Logs-Url: https://github.com/dotnet/runtime/sessions/42d4769b-0756-4ab1-aaae-f73cf4cfaa3d Co-authored-by: mrek-msft <188900745+mrek-msft@users.noreply.github.com>

Forward IO exceptions to OnLoadException

cbb97be

Copilot AI review requested due to automatic review settings March 25, 2026 15:31

github-actions bot added the area-Extensions-Configuration label Mar 25, 2026

dotnet-policy-service bot assigned mrek-msft Mar 25, 2026

Copilot started reviewing on behalf of mrek-msft March 25, 2026 15:32 View session

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mrek-msft marked this pull request as draft March 25, 2026 15:36

Removed duplicate Data dict recreation

64d03ea

This was referenced Mar 26, 2026

The Operation will be canceled. The next steps may not contain expected logs. dotnet/dnceng#3008

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[android-arm64] The Operation will be canceled. The next steps may not contain expected logs. dotnet/dnceng#6408

Open

Add tests

018c6f6

Copilot AI review requested due to automatic review settings March 26, 2026 16:02

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tarekgh added area-Extensions-FileSystem and removed area-Extensions-Configuration labels Mar 26, 2026

mrek-msft added 4 commits March 26, 2026 17:41

Throw alaways InvalidDataException and clear Data only on data error.

a6e7d92

Improve test attributes assignment.

7e07276

Fix typos

afaa6a4

Change exception back to rpopagating IOException directly and improve…

0a76a86

… file path formatting logic.

Copilot AI review requested due to automatic review settings March 26, 2026 16:59

Copilot started reviewing on behalf of mrek-msft March 26, 2026 17:00 View session

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mrek-msft added 6 commits March 26, 2026 18:10

Fix missing PhysicalPath in error string shown file name selection

4a972f6

Improve comment.

7096d71

Remove duplicate test.

a77d5ca

Add missing ActiveIssue attribute to possibly flaky test.

6f9e61c

Add comment recommended by Copilot

af033ee

Check for type of observed exception.

2ce4531

mrek-msft assigned tarekgh and unassigned svick, cincuranet, tarekgh and rosebyte Apr 1, 2026

mrek-msft requested review from cincuranet, rosebyte, svick and tarekgh April 1, 2026 12:31

tarekgh added this to the 11.0.0 milestone Apr 1, 2026

tarekgh reviewed Apr 1, 2026

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This was referenced Apr 1, 2026

Unable to pull image from mcr.microsoft.com #117164

Open

TestNativeDigits fails for ur-IN on Apple platforms (xunit v3 exposed previously non-running test) #125933

Open

Improve FileLoadExceptionContext.Exception comment as requested in PR…

ef8b329

… review

rosebyte reviewed Apr 7, 2026

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Removal of nested try..catch and handling deletion explicitly

0708b4f

rosebyte requested a review from Copilot April 8, 2026 14:28

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mrek-msft added 3 commits April 9, 2026 15:32

Handle file not found in the same way on both paths.

3e38ca4

Fix whitespace formatting

6e934f5

Copilot improved comment

ce0f578

Copilot AI mentioned this pull request Apr 11, 2026

Fix WasmTestOnChrome: exclude browser/wasi from gen-debug-dump-docs.py helix post-command #126789

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mrek-msft commented Mar 25, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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dotnet-policy-service bot commented Mar 26, 2026

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svick commented Apr 2, 2026

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mrek-msft commented Mar 25, 2026 •

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