Add ExceptionIfMissing static parameter to JsonProvider and XmlProvider

[Copilot]

The Repo Assist workflow attempted to implement ExceptionIfMissing for JsonProvider and XmlProvider but the patch failed to apply due to a concurrent merge. This implements those changes directly.

Changes

New static parameter: ExceptionIfMissing

• Added to both JsonProvider and XmlProvider (defaults to false for backward compatibility)
• When true, accessing a non-optional field absent from the data raises an exception instead of silently returning "" (string) or NaN (float)

Runtime

• JsonRuntime.GetNonOptionalValueStrict — throws on missing JSON fields
• TextRuntime.GetNonOptionalValueStrict — throws on missing XML/CSV fields

Design-time codegen

• JsonGenerationContext and XmlGenerationContext carry ExceptionIfMissing
• ConversionsGenerator.convertStringValue and JsonConversionsGenerator.convertJsonValue select between GetNonOptionalValue and GetNonOptionalValueStrict based on the flag
• TypeProviderInstantiation updated with the new field

Usage

// ExceptionIfMissing=false (default) — returns empty string for missing field
type JsonLenient = JsonProvider<"""{"name": "Alice", "age": 30}""">
let doc = JsonLenient.Parse("""{"age": 30}""")
doc.Name  // ""

// ExceptionIfMissing=true — throws for missing field
type JsonStrict = JsonProvider<"""{"name": "Alice", "age": 30}""", ExceptionIfMissing=true>
let doc2 = JsonStrict.Parse("""{"age": 30}""")
doc2.Name  // raises exception: "'name' is missing"

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• api.worldbank.org
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet /usr/share/dotnet/sdk/8.0.124/FSharp/fsc.dll @/tmp/MSBuildTempJsopSi/tmpb4da9a1a93714c6b98f1703eb9a3321c.rsp (dns block)
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet /usr/share/dotnet/sdk/8.0.124/FSharp/fsc.dll @/tmp/MSBuildTempWprtaM/tmp19c92066e48a48139df9357346bd807e.rsp (dns block)
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet /usr/share/dotnet/sdk/8.0.124/FSharp/fsc.dll @/tmp/MSBuildTempEbPPTk/tmpf7fd0ae7d5014b19aea670fbb04318b7.rsp (dns block)
• schemas.microsoft.com
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.deps.json /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/testhost.dll --port 46539 --endpoint 127.0.0.1:046539 --role client --parentprocessid 9173 --telemetryoptedin false (dns block)
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.deps.json /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/testhost.dll --port 44603 --endpoint 127.0.0.1:044603 --role client --parentprocessid 9319 --telemetryoptedin false (dns block)
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.deps.json /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/testhost.dll --port 44795 --endpoint 127.0.0.1:044795 --role client --parentprocessid 9460 --telemetryoptedin false (dns block)
• tomasp.net
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.deps.json /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/testhost.dll --port 46539 --endpoint 127.0.0.1:046539 --role client --parentprocessid 9173 --telemetryoptedin false (dns block)
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.deps.json /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/testhost.dll --port 44603 --endpoint 127.0.0.1:044603 --role client --parentprocessid 9319 --telemetryoptedin false (dns block)
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/FSharp.Data.DesignTime.Tests.deps.json /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.DesignTime.Tests/bin/Debug/net8.0/testhost.dll --port 44795 --endpoint 127.0.0.1:044795 --role client --parentprocessid 9460 --telemetryoptedin false (dns block)
• www.google.com
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.Core.Tests/bin/Debug/net8.0/FSharp.Data.Core.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.Core.Tests/bin/Debug/net8.0/FSharp.Data.Core.Tests.deps.json /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.Core.Tests/bin/Debug/net8.0/testhost.dll --port 46425 --endpoint 127.0.0.1:046425 --role client --parentprocessid 10145 --telemetryoptedin false (dns block)
  • Triggering command: /usr/share/dotnet/dotnet /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.Core.Tests/bin/Debug/net8.0/FSharp.Data.Core.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.Core.Tests/bin/Debug/net8.0/FSharp.Data.Core.Tests.deps.json /home/REDACTED/work/FSharp.Data/FSharp.Data/tests/FSharp.Data.Core.Tests/bin/Debug/net8.0/testhost.dll --port 35223 --endpoint 127.0.0.1:035223 --role client --parentprocessid 10307 --telemetryoptedin false (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[aw] Repo Assist failed</issue_title>
<issue_description>### Workflow Failure

Workflow: Repo Assist
Branch: main
Run: https://github.com/fsprojects/FSharp.Data/actions/runs/22560377564

⚠️ Code Push Failed: A code push safe output failed, and subsequent safe outputs were cancelled.
Code Push Errors:

• push_to_pull_request_branch: Failed to apply patch

Action Required

Option 1: Assign this issue to Copilot

Assign this issue to Copilot using the agentic-workflows sub-agent to automatically debug and fix the workflow failure.

Option 2: Manually invoke the agent

Debug this workflow failure using your favorite Agent CLI and the agentic-workflows prompt.

• Start your agent
• Load the agentic-workflows prompt from .github/agents/agentic-workflows.agent.md or https://github.com/github/gh-aw/blob/main/.github/agents/agentic-workflows.agent.md
• Type debug the agentic workflow repo-assist failure in https://github.com/fsprojects/FSharp.Data/actions/runs/22560377564

Generated from Repo Assist

• expires on Mar 9, 2026, 3:59 AM UTC

Comments on the Issue (you are @copilot in this section)

• Fixes [aw] Repo Assist failed #1687

---

🔒 GitHub Advanced Security automatically protects Copilot coding agent pull requests. You can protect all pull requests by enabling Advanced Security for your repositories. Learn more about Advanced Security.