SessionFs structured error contract + workspace E2E tests by SteveSandersonMS · Pull Request #1102 · github/copilot-sdk

SteveSandersonMS · 2026-04-17T15:27:00Z

Summary

Updates the Node.js SDK to support the new sessionFs structured error contract from github/copilot-agent-runtime#6479.

Changes

*Regenerated
pc.ts* from updated \�pi.schema.json\ — all sessionFs result types now include an optional \�rror\ object:
\\ ypescript
error?: { code: 'ENOENT' | 'UNKNOWN'; message?: string }
\\
Updated test handler (\createTestSessionFsHandler) to catch native fs errors and return { error: { code, message } }\ instead of throwing — this matches the new RPC contract where error classification is part of the response rather than relying on exception serialization
Added 2 E2E tests proving workspace files (workspace.yaml, plan.md) are written through sessionFs

Why

\�scode-jsonrpc\ \ResponseError\ loses the Node.js .code\ string property during serialization. The runtime's \WorkspaceManager.loadWorkspace()\ checks \�rror.code === 'ENOENT'\ to handle missing workspaces — without this contract, workspace initialization silently fails over SDK sessions.

Depends on

github/copilot-agent-runtime#6479

…e tests - Regenerate rpc.ts from updated api.schema.json with structured error type (error?: { code: 'ENOENT' | 'UNKNOWN', message?: string }) on all sessionFs results - Update createTestSessionFsHandler to catch fs errors and return error objects instead of throwing (matches the new RPC contract) - Add E2E tests for workspace metadata and plan.md written via sessionFs - Add test snapshots for new workspace tests Depends on: github/copilot-agent-runtime#6479 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Two issues caused duplicate type generation in json-schema-to-typescript: 1. $ ef objects with sibling keywords (e.g. description) were treated as new inline types instead of reusing the referenced definition. Fix: strip all sibling keywords from $ ef objects in normalizeSchemaForTypeScript. 2. withSharedDefinitions copies definitions into $defs when $defs is empty, then normalizeSchemaForTypeScript aliased collisions as $defs_X. Since definitions entries go through the full pipeline (title-stripping, ref-reuse) but $defs copies don't, they diverge. Fix: when a key exists in both, prefer the definitions entry and drop the $defs duplicate. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The runtime schema uses anyOf [{not:{}}, {$ref: ...}] for optional results (e.g., writeFile returns SessionFsError or undefined). Previously all 4 codegen scripts only recognized {type: 'null'} as null-like, producing incorrect wrapper types. Changes: - utils.ts: Add getNullableInner() to detect {not:{}} null patterns - typescript.ts: Emit 'T | undefined' for nullable results - csharp.ts: Emit 'Task<T?>' for nullable results - python.ts: Emit 'T | None' for nullable results - go.ts: Emit '*T' (pointer) for nullable results - Regenerated all 4 languages - Fixed C# test handler to use Task<SessionFsError?> - Fixed Go session.go Vision type rename Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Introduce a SessionFsProvider base class/interface in each language that wraps the generated SessionFsHandler RPC contract with idiomatic patterns: - C#: Abstract class with virtual methods that throw on error - Go: Interface with (value, error) returns; unexported adapter - TypeScript: Interface + createSessionFsAdapter() wrapper function - Python: ABC + create_session_fs_adapter() wrapper function Each adapter catches exceptions/errors and converts them to SessionFsError results (ENOENT/UNKNOWN). Public APIs now use SessionFsProvider exclusively. Also fixes C# serialization crash (CommonErrorData not registered in source-generated JSON context) and adds shared Warning-level logging to all C# E2E tests. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

    session_event_from_dict,
 )
 from .tools import Tool, ToolHandler, ToolInvocation, ToolResult
+from .session_fs_provider import SessionFsProvider


The _dispatch_request method was converting None handler results to {} (empty dict) before sending JSON-RPC responses. The runtime expects null for void operations (mkdir, writeFile, appendFile). Receiving {} caused the runtime to fall back to local filesystem for subsequent writes. Also removes debug tracing from session_fs_provider.py adapter. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Copilot

Pull request overview

Updates the SDKs/codegen to support the new structured sessionFs error contract (returning classified errors as part of results instead of relying on exception serialization), and adds E2E coverage asserting workspace state is persisted through sessionFs.

Changes:

Regenerates RPC types and updates codegen to better handle nullable anyOf result wrappers and definition deduplication.
Introduces idiomatic SessionFsProvider abstractions + adapters (Node/Python/Go/.NET) that translate thrown/native errors into the structured SessionFsError contract.
Adds new E2E tests + snapshots verifying workspace.yaml and plan.md are written via sessionFs.

Show a summary per file

File	Description
test/snapshots/session_fs/should_write_workspace_metadata_via_sessionfs.yaml	New snapshot for workspace metadata write scenario.
test/snapshots/session_fs/should_persist_plan_md_via_sessionfs.yaml	New snapshot for plan persistence scenario.
scripts/codegen/utils.ts	Adds `getNullableInner` helper and minor clone logic tweak.
scripts/codegen/typescript.ts	Updates TS codegen to handle nullable results and `$ref` normalization.
scripts/codegen/python.ts	Updates Python codegen for nullable results and reduces quicktype duplicate-type noise.
scripts/codegen/go.ts	Updates Go codegen for nullable results/anyOf handling and quicktype duplicate-type noise.
scripts/codegen/csharp.ts	Updates C# codegen for nullable anyOf and discriminated unions.
python/e2e/test_session_fs.py	Adds E2E tests for workspace.yaml + plan.md; refactors test FS handler to provider style.
python/copilot/session_fs_provider.py	Adds provider abstraction + adapter that maps exceptions to `SessionFSError`.
python/copilot/session.py	Updates generated type names and session-fs handler typing to use provider abstraction.
python/copilot/generated/session_events.py	Regenerated session-events types (new fields and renames).
python/copilot/client.py	Wraps user provider with adapter when sessionFs is enabled.
python/copilot/_jsonrpc.py	Allows request handlers to return `None` (JSON `null`) for nullable result contract.
python/copilot/init.py	Exposes provider/adapter types in public Python package surface.
nodejs/test/e2e/session_fs.test.ts	Adds E2E tests for workspace.yaml + plan.md; updates test FS handler to provider style.
nodejs/src/types.ts	Switches public session fs handler type to provider; updates permission kind union.
nodejs/src/sessionFsProvider.ts	Adds provider abstraction + adapter that maps Node fs errors to `SessionFsError`.
nodejs/src/index.ts	Re-exports provider/adapter types from public entrypoint.
nodejs/src/generated/rpc.ts	Regenerated RPC types reflecting structured sessionFs errors + other schema updates.
nodejs/src/client.ts	Wraps user provider with adapter when sessionFs is enabled.
go/types.go	Public API now uses `SessionFsProvider`; fixes model capabilities vision alias.
go/session_fs_provider.go	Adds provider interface + adapter mapping Go errors to `SessionFSError`.
go/session.go	Updates enums/types for elicitation/permissions; removes unnecessary model-capabilities conversion.
go/internal/e2e/session_fs_test.go	Adds E2E coverage for workspace.yaml + plan.md; updates test provider impl.
go/generated_session_events.go	Regenerated session-events types (new fields and renames).
go/client.go	Wraps user provider with adapter when sessionFs is enabled.
dotnet/test/SessionFsTests.cs	Adds E2E-style tests for workspace.yaml + plan.md; updates test handler base type.
dotnet/test/SessionEventSerializationTests.cs	Updates shutdown model metrics test to typed objects.
dotnet/test/Harness/E2ETestContext.cs	Adds optional logger plumbing into created clients.
dotnet/test/Harness/E2ETestBase.cs	Adds xUnit logger forwarding warnings+ into test output.
dotnet/src/Types.cs	Session config now uses `SessionFsProvider` instead of `ISessionFsHandler`.
dotnet/src/SessionFsProvider.cs	Adds base class implementing structured error mapping for sessionFs.
dotnet/src/Session.cs	Updates permission handling to new generated RPC contract types.
dotnet/src/Generated/SessionEvents.cs	Regenerated session-events types and adds new nested metric/usage types.
dotnet/src/Generated/Rpc.cs	Regenerated RPC types including `SessionFsError` and polymorphic `PermissionDecision`.
dotnet/src/Client.cs	Updates sessionFs handler plumbing + JSON serializer context additions.

Copilot's findings

Files reviewed: 32/39 changed files
Comments generated: 5

Copilot · 2026-04-20T19:16:49Z

 export interface PermissionRequest {
-    kind: "shell" | "write" | "mcp" | "read" | "url" | "custom-tool";
+    kind: "shell" | "write" | "mcp" | "read" | "url" | "custom-tool" | "memory" | "hook";
    toolCallId?: string;


PermissionRequest no longer has the [key: string]: unknown index signature, so permission handlers can’t access request-specific fields (e.g., path/intention/commands) without type assertions. Consider restoring the index signature or changing this type to a discriminated union of the concrete permission request shapes so handlers remain usable and forward-compatible.

Suggested change

toolCallId?: string;

toolCallId?: string;

[key: string]: unknown;

Copilot · 2026-04-20T19:16:49Z

+        async rm(path: string): Promise<void> {
+            await provider.unlink(sp(path));


This rm implementation ignores the recursive/force semantics of the SessionFsProvider contract and always calls unlink. If the runtime requests directory deletion (recursive) or force removal of a missing path, this will fail unexpectedly; please implement those flags (e.g., choose unlink vs rm/recursive delete and swallow ENOENT when force is true).

Suggested change

async rm(path: string): Promise<void> {

await provider.unlink(sp(path));

async rm(path: string, recursive?: boolean, force?: boolean): Promise<void> {

const target = sp(path);

try {

if (recursive) {

await provider.rm(target, { recursive: true, force: !!force });

} else {

await provider.unlink(target);

}

} catch (error) {

if (

force &&

typeof error === "object" &&

error !== null &&

"code" in error &&

error.code === "ENOENT"

) {

return;

}

throw error;

}

Copilot · 2026-04-20T19:16:50Z

+    async def rm(self, path: str, recursive: bool, force: bool) -> None:
+        self._path(path).unlink()


rm() currently always unlinks a file and ignores the recursive and force parameters. This will break callers that expect directory removal or that pass force=True for missing paths; please implement directory deletion when recursive is true and swallow ENOENT when force is true.

Copilot · 2026-04-20T19:16:50Z

+            now = datetime.now()
+            err = _to_session_fs_error(exc)
+            return SessionFSStatResult(
+                is_file=False,
+                is_directory=False,
+                size=0,
+                mtime=now,
+                birthtime=now,
+                error=err,


On stat failure, the adapter populates mtime/birthtime with datetime.now() (naive/local time). Since the generated RPC types serialize datetimes via isoformat(), this can yield timestamps without timezone offsets and inconsistent behavior vs the UTC-aware success path; consider using a timezone-aware UTC timestamp for these fallback fields.

Copilot · 2026-04-20T19:16:50Z

            var result = await handler(permissionRequest, invocation);
            if (result.Kind == new PermissionRequestResultKind("no-result"))
            {
                return;
            }
-            await Rpc.Permissions.HandlePendingPermissionRequestAsync(requestId, result);
+            await Rpc.Permissions.HandlePendingPermissionRequestAsync(requestId, new PermissionDecision { Kind = result.Kind.Value });
        }


HandlePendingPermissionRequestAsync now expects a PermissionDecision (polymorphic). Creating new PermissionDecision { Kind = result.Kind.Value } drops required fields for some variants (e.g., denied-by-rules requires rules, content-exclusion requires path/message), which can lead to invalid payloads if a handler returns those kinds. Consider constraining the public PermissionRequestResultKind values to only variants representable by the SDK, or map each supported kind to the correct derived PermissionDecision* type and reject unsupported kinds.

SteveSandersonMS force-pushed the stevesa/workspace-manager-on-sessionfs branch from ae9d745 to b39f0de Compare April 20, 2026 13:09

SteveSandersonMS and others added 8 commits April 20, 2026 14:27

Codegen updates and fixes

1d46315

More codegen fixes

2209a43

So many more codegen fixes

507f2da

Logging for C# e2e tests

9b8a314

Fix C# SessionFs tests

240ceda

github-code-quality bot found potential problems Apr 20, 2026

View reviewed changes

Comment thread python/copilot/session.py

session_event_from_dict,

)

from .tools import Tool, ToolHandler, ToolInvocation, ToolResult

from .session_fs_provider import SessionFsProvider

github-code-quality bot found potential problems Apr 20, 2026

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SteveSandersonMS marked this pull request as ready for review April 20, 2026 19:10

SteveSandersonMS requested a review from a team as a code owner April 20, 2026 19:10

Copilot AI review requested due to automatic review settings April 20, 2026 19:10

Copilot started reviewing on behalf of SteveSandersonMS April 20, 2026 19:11 View session

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SessionFs structured error contract + workspace E2E tests#1102

SessionFs structured error contract + workspace E2E tests#1102
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SteveSandersonMS commented Apr 17, 2026

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	toolCallId?: string;
	toolCallId?: string;
	[key: string]: unknown;

		async rm(path: string): Promise<void> {
		await provider.unlink(sp(path));

-        async rm(path: string): Promise<void> {
-            await provider.unlink(sp(path));
+        async rm(path: string, recursive?: boolean, force?: boolean): Promise<void> {
+            const target = sp(path);
+            try {
+                if (recursive) {
+                    await provider.rm(target, { recursive: true, force: !!force });
+                } else {
+                    await provider.unlink(target);
+                }
+            } catch (error) {
+                if (
+                    force &&
+                    typeof error === "object" &&
+                    error !== null &&
+                    "code" in error &&
+                    error.code === "ENOENT"
+                ) {
+                    return;
+                }
+                throw error;
+            }

		async def rm(self, path: str, recursive: bool, force: bool) -> None:
		self._path(path).unlink()

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SteveSandersonMS commented Apr 17, 2026

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