refactor: implement fallback API connection

[AMIRKHANEF]

Close: #2015

Summary by CodeRabbit

• Bug Fixes
  • Enhanced API connection reliability with exponential backoff retry logic for failed connections, capping retry attempts at a maximum threshold.
  • Improved auto-mode endpoint fallback handling to better manage connection failures and error recovery.

[coderabbitai]

Walkthrough

Refactors ApiProvider connection flow to async/await, adds MAX_RETRIES and exponential backoff, makes connection attempts sequential (awaiting handleAutoMode, connectToEndpoint, connectToLightClient), updates connectToEndpoint to use throwOnConnect and explicit disconnect/reset on failure, and adds retry/fallback to AUTO_MODE_DEFAULT_ENDPOINT with bounded retries.

Changes

Cohort / File(s)

Summary

Api connection logic packages/extension-ui/src/Popup/contexts/ApiProvider.tsx

Introduced MAX_RETRIES; getApi signature extended with retryCount?: number and performs exponential-backoff retries up to MAX_RETRIES, returning undefined after; requestApiConnection made async and now awaits handleAutoMode, connectToEndpoint, and connectToLightClient sequentially; connectToEndpoint creates WsProvider/ApiPromise with throwOnConnect: true, disconnects and resolves pending connections as undefined on failure, and resets endpoint to AUTO_MODE_DEFAULT_ENDPOINT when in auto mode; logging adjusted for retry/backoff flow.

Sequence Diagram(s)

sequenceDiagram
    participant Caller
    participant getApi
    participant requestApiConnection as requestApiConnection<br/>(async)
    participant handleAutoMode
    participant connectToEndpoint
    participant connectToLightClient

    Caller->>getApi: getApi(genesisHash,endpoints, retryCount?)
    alt No endpoint selected
        getApi->>getApi: set AUTO_MODE_DEFAULT_ENDPOINT if needed
    end
    getApi->>requestApiConnection: await requestApiConnection()
    rect rgb(220, 235, 255)
        Note over requestApiConnection: Sequential connection steps
        requestApiConnection->>handleAutoMode: await handleAutoMode()
        handleAutoMode-->>requestApiConnection: resolved endpoint
        requestApiConnection->>connectToEndpoint: await connectToEndpoint() (throwOnConnect:true)
        alt connect success
            connectToEndpoint-->>requestApiConnection: ApiPromise
            requestApiConnection->>connectToLightClient: await connectToLightClient()
            connectToLightClient-->>requestApiConnection: light client ready
        else connect failure
            connectToEndpoint->>connectToEndpoint: disconnect wsProvider, reset endpoint if AUTO
            connectToEndpoint-->>requestApiConnection: throw error
        end
    end
    rect rgb(255, 235, 230)
        Note over getApi: Retry & backoff
        requestApiConnection-->>getApi: success or error
        alt error
            getApi->>getApi: log, wait (exponential backoff)
            getApi->>getApi: if retryCount < MAX_RETRIES -> recursive getApi(retryCount+1)
        else success
            getApi-->>Caller: return ApiPromise
        end
    end

Loading

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~45 minutes

• Areas needing extra attention:
  • verify exponential backoff math and bounds for MAX_RETRIES
  • ensure recursive getApi retries cannot cause unbounded recursion/state corruption
  • confirm wsProvider lifecycle: creation, disconnect, and cleanup on failure
  • check that awaiting handleAutoMode eliminates prior race conditions and that state mutations are safe
  • validate that pending connection resolvers are consistently resolved to undefined on failure

Poem

🐰
I hopped through sockets, one by one,
Awaiting each connect till done,
If endpoints trip, I nudge to “auto”,
Retry with care, then gently go,
A rabbit’s sequence, steady, fun.

Pre-merge checks and finishing touches

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main change: implementing fallback API connection logic, which directly aligns with the core objective.
Linked Issues check	✅ Passed	The pull request implements fallback API connection with auto-mode switching when endpoints fail, matching the primary objective in issue #2015.
Out of Scope Changes check	✅ Passed	All changes in ApiProvider.tsx are directly related to implementing the fallback mechanism with retry logic and auto-mode handling as specified in issue #2015.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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[coderabbitai]

Actionable comments posted: 3

🧹 Nitpick comments (1)

packages/extension-ui/src/Popup/contexts/ApiProvider.tsx (1)

284-285: Update comment for clarity.

The comment says "Start connection" but the await means the code waits for the connection to complete, not just initiate it.

Apply this diff:

-      // Start connection
+      // Request connection and wait for completion
       await requestApiConnection(genesisHash, endpoint, endpoints);

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between e22bf0f and db9bc02.

📒 Files selected for processing (1)

• packages/extension-ui/src/Popup/contexts/ApiProvider.tsx (4 hunks)

🧰 Additional context used

🧬 Code graph analysis (1)

packages/extension-ui/src/Popup/contexts/ApiProvider.tsx (2)

packages/extension-polkagate/src/util/constants.ts (1)

• AUTO_MODE_DEFAULT_ENDPOINT (270-275)

packages/extension-polkagate/src/util/types.ts (2)

• EndpointType (894-899)
• DropdownOption (876-879)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (2)

• GitHub Check: build
• GitHub Check: Analyze (javascript)

[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

packages/extension-ui/src/Popup/contexts/ApiProvider.tsx (1)

16-16: Reuse shared MAX_RETRIES constant.

There is already a MAX_RETRIES exported from packages/extension-polkagate/src/util/api/utils.ts (value 7). Redefining a different value here risks divergence and makes tuning harder to reason about. Prefer importing the shared constant (or centralizing configuration) so retry limits stay consistent across the codebase.

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between db9bc02 and d81910c.

📒 Files selected for processing (1)

• packages/extension-ui/src/Popup/contexts/ApiProvider.tsx (5 hunks)

🧰 Additional context used

🧠 Learnings (1)

📚 Learning: 2024-08-31T05:19:02.468Z

Learnt from: AMIRKHANEF
Repo: PolkaGate/extension PR: 1467
File: packages/extension-polkagate/src/util/types.ts:0-0
Timestamp: 2024-08-31T05:19:02.468Z
Learning: The `SavedEndpoint` interface in the `packages/extension-polkagate/src/util/types.ts` file has a property named `isOnManual`, which indicates whether the endpoint is in manual mode.

Applied to files:

• packages/extension-ui/src/Popup/contexts/ApiProvider.tsx

🧬 Code graph analysis (1)

packages/extension-ui/src/Popup/contexts/ApiProvider.tsx (3)

packages/extension-polkagate/src/util/api/utils.ts (1)

• MAX_RETRIES (5-5)

packages/extension-polkagate/src/util/constants.ts (1)

• AUTO_MODE_DEFAULT_ENDPOINT (270-275)

packages/extension-polkagate/src/util/types.ts (2)

• EndpointType (894-899)
• DropdownOption (876-879)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: build