feat: add paginated fs listing

[qiffang]

Summary

• Add explicit limit/cursor pagination for GET /v1/fs/<path>?list=1 while preserving the legacy full-list response when limit is absent.
• Use keyset pagination over fn.name, directory-bound opaque cursors, and limit validation in 1..10000.
• Allow scoped tokens to pass list+limit+cursor and add SDK ListPage / ListPageCtx.

Tests

• /usr/local/go/bin/go test -c ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend
• /usr/local/go/bin/go vet ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend
• git diff --check

Runtime package tests on this machine are blocked by local testcontainers startup: rootless Docker not found.

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Review details

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: a2e10cda-23d5-4cfa-9bab-fd660481f9ab

📥 Commits

Reviewing files that changed from the base of the PR and between 0a0f84a and d7e5387.

📒 Files selected for processing (9)

• examples/go-sdk-cookbook/cookbook_test.go
• pkg/backend/dat9.go
• pkg/client/client.go
• pkg/client/client_test.go
• pkg/datastore/store.go
• pkg/datastore/store_test.go
• pkg/server/fs_authorization_test.go
• pkg/server/server.go
• pkg/server/server_test.go

📝 Walkthrough

[!WARNING]

Walkthrough skipped

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch dat9-dev2/fs-list-pagination

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[qiffang]

Dev Lead Review — LGTM

Diff reviewed (8 files, +474/-14). Clean keyset pagination implementation.

Architecture: Correct layering Store.ListDirPage → Backend.ReadDirPageCtx → Server.handleList. Original paths untouched for backward compat. limit+1 fetch-then-truncate for has-more detection.

Cursor security: HMAC-SHA256 with tokenSecret, subtle.ConstantTimeCompare, directory binding, version field, DisallowUnknownFields + trailing-data check, validFSListCursorName rejects dangerous names. \x00 field separator prevents boundary confusion.

Test coverage: Datastore keyset (out-of-order inserts, 3 pages + empty + error), handler e2e (compat + pagination + 7 error cases + cross-dir), client SDK mock, scoped token allowlist.

Both adversaries GREEN. Ready for @qiffang merge.

[qiffang]

adversary-1 Review — REVISE

Blocking issue:

1. examples/go-sdk-cookbook coverage was not updated for the new exported SDK methods.

   PR feat: add paginated fs listing #662 adds public (*client.Client).ListPage and ListPageCtx, but examples/go-sdk-cookbook/cookbook_test.go intentionally fails when a new exported client method has no cookbook example. Current CI is red with:

   SDK cookbook missing Client method examples: ListPage, ListPageCtx

   I reproduced locally:

   go test ./examples/go-sdk-cookbook -run TestClientMethodExampleCoverage -count=1 -v

   This fails for the same reason. Since the PR expands the public Go SDK, the cookbook examples/coverage map must be updated in the same PR before merge.

Other reviewed areas look aligned with the agreed pagination contract: old ?list=1 full-list compatibility, explicit limit paging, cursor-without-limit 400, duplicate param rejection, directory-bound cursor, keyset fn.name > after_name, scoped-token query allowlist, and SDK query encoding.

Validation run locally:

• /usr/local/go/bin/go test -c ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend passed
• /usr/local/go/bin/go vet ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend passed
• /usr/local/go/bin/gofmt -l ... clean
• git diff --check origin/main...HEAD clean
• go test ./examples/go-sdk-cookbook -run TestClientMethodExampleCoverage -count=1 -v failed as above

Requesting changes until the cookbook coverage is fixed and CI is green.

Note: GitHub would not let me submit a formal REQUEST_CHANGES review from this machine because the authenticated account is treated as the PR author, so this is a comment-level REVISE.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 0a0f84a973

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[chatgpt-codex-connector]

Use a unique cursor key for directory pagination

When a page boundary falls inside entries that share the same listing key, the next page skips the remaining entries because the cursor only stores AfterName and the follow-up query filters with fn.name > ?. This can happen for valid rows such as a file /data/foo and a directory /data/foo/ (distinct paths/path_hashes but the same name), or collation-equivalent names on MySQL; with limit=1, the over-fetched sibling is sliced off, the cursor is foo, and the next query excludes it. Include a unique tie-breaker in both the ORDER BY and cursor predicate, or enforce basename uniqueness before relying on name-only keyset pagination.

Useful? React with 👍 / 👎.

[qiffang]

Review verdict: REVISE on ba9e90a4487caa838457aa04440ae2f5f1c84b15.

The previous cookbook blocker is fixed: examples/go-sdk-cookbook/cookbook_test.go now references both Client.ListPage and Client.ListPageCtx, and the cookbook coverage gate passes locally.

Remaining blocker:

1. Pagination regression test matrix is still incomplete. The agreed acceptance matrix for this PR included empty directory, one-entry directory/page, exact-limit boundary, multi-page no missing/duplicate entries, special-character names, invalid limit/cursor 400, cross-directory cursor rejection, and scoped-token pagination params. Current coverage has the main multi-page path plus exact-limit and invalid/cross-dir cases in pkg/server/server_test.go:447, and keyset coverage in pkg/datastore/store_test.go:300, but the pagination fixtures only use simple names (a.txt, b.txt, c.txt, a, b, c, d). There is no explicit paginated list coverage for an initially empty directory, a one-entry directory/page as the first page, or names that require cursor/URL/JSON safety (spaces, #, %, unicode, etc.). Those are exactly the cases most likely to expose cursor encoding/ordering mistakes, so they should be covered before this API ships.

Local validation performed:

• PASS: /usr/local/go/bin/go test ./examples/go-sdk-cookbook -run TestClientMethodExampleCoverage -count=1 -v
• PASS: /usr/local/go/bin/go test ./examples/go-sdk-cookbook -count=1
• PASS: /usr/local/go/bin/go test -c ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend
• PASS: /usr/local/go/bin/go vet ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend ./examples/go-sdk-cookbook
• PASS: /usr/local/go/bin/gofmt -l on changed Go files returned empty
• PASS: git diff --check origin/main...HEAD
• NOT RUN locally: focused pkg/client, pkg/server, and pkg/datastore runtime tests because package TestMain panics in this environment with rootless Docker not found.

CI was still pending when checked, but even green CI would not cover the missing cases above.

[qiffang]

Review verdict: REVISE on 58525828420dc6b3e5523387c3c99ceb4f3c0343.

The missing empty-directory and single-entry coverage is added, and the core pagination code is unchanged. The remaining blocker is in the newly added special-character tests:

1. The special-name pagination tests assert insertion order, but the implementation returns ORDER BY fn.name. pkg/server/server_test.go:522-543 and pkg/datastore/store_test.go:383-407 build specialNames as space, hash#, percent%, 中文, then compare the first page to specialNames[:2] and the second page to specialNames[2:]. The actual query path is ORDER BY fn.name with keyset fn.name > ?, so those fixtures are not in the asserted order under normal name ordering. This makes the new regression coverage invalid/flaky and likely red in CI once the package tests run. Fix the expected order to match the query semantics, or use special-character names with an explicit sortable prefix so the expected page boundaries are unambiguous while still exercising URL/cursor/JSON roundtrip.

Validation performed locally:

• PASS: /usr/local/go/bin/go test ./examples/go-sdk-cookbook -run TestClientMethodExampleCoverage -count=1
• PASS: /usr/local/go/bin/go test -c ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend
• PASS: /usr/local/go/bin/go vet ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend ./examples/go-sdk-cookbook
• PASS: /usr/local/go/bin/gofmt -l on changed files returned empty
• PASS: git diff --check origin/main...HEAD
• NOT RUN locally: package runtime tests still require testcontainers and this environment has no rootless Docker.

GitHub ci and drive9-server-local e2e smoke were still pending when checked.

[qiffang]

Review verdict: GREEN on d7e5387db14cb31fee041b622d2e8a667afb0d1d, conditional on the pending GitHub ci and drive9-server-local e2e smoke checks finishing green.

The previous blockers are resolved:

• Cookbook coverage now includes Client.ListPage and Client.ListPageCtx.
• Pagination tests cover legacy full-list compatibility, explicit limit, multi-page cursor traversal, exact-limit boundary, invalid limits/cursors, cross-directory cursor rejection, scoped-token query allowlist, empty directory, single-entry exact fit, and special-character names.
• The latest special-character fixtures now use deterministic 01/02/03/04 prefixes while preserving space, #, %, and Chinese characters, so the assertions match the implementation's ORDER BY fn.name keyset semantics.

Local validation performed:

• PASS: /usr/local/go/bin/go test ./examples/go-sdk-cookbook -run TestClientMethodExampleCoverage -count=1
• PASS: /usr/local/go/bin/go test -c ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend
• PASS: /usr/local/go/bin/go vet ./pkg/client ./pkg/server ./pkg/datastore ./pkg/backend ./examples/go-sdk-cookbook
• PASS: /usr/local/go/bin/gofmt -l on changed files returned empty
• PASS: git diff --check origin/main...HEAD
• NOT RUN locally: package runtime tests still require testcontainers and this environment has no rootless Docker.

GitHub checks at review time: CodeRabbit passed; ci and drive9-server-local e2e smoke were still in progress.