test(x): mock StrategyFinder dialers in smart integration tests

[fortuna]

Simplify smart integration tests by using mock dialers and an error fallback parser. This removes the need for the nettest build tag and external network connections.

[greptile-apps]

Greptile Summary

This PR converts smart strategy finder integration tests and two TLS stream dialer tests from live-network to fully hermetic by introducing mock dialers and local httptest servers. The test logic is sound — error chains propagate correctly through the dns.nestedError wrapping, and the mock scenarios accurately replicate the failure conditions being tested.

Confidence Score: 4/5

Safe to merge — all changes are in test files and the mock logic correctly replicates the failure scenarios the tests were designed to exercise.

The conversion from live-network tests to hermetic mocks is logically sound: error chains are traced correctly, the captive-portal server closes connections immediately reproducing the right TLS failure, and the untrusted-cert server uses httptest self-signed cert as intended. The only issues are a misordered import block in stream_dialer_test.go and a semantically misleading error string in mockStreamDialer's fallback branch — neither affects correctness or CI.

The import ordering in transport/tls/stream_dialer_test.go is the only thing worth a quick second look.

Important Files Changed

Filename	Overview
x/smart/integrationtest/integration_test.go	Removes nettest build tag and replaces live network calls with mock dialers; logic is correct but the generic error message used by the mock for non-DNS connections is slightly misleading.
transport/tls/stream_dialer_test.go	Converts two live-network TLS tests to hermetic local-server variants using generated certs; imports are not in standard alphabetical order within the stdlib group.

Sequence Diagram

%%{init: {'theme': 'neutral'}}%%
sequenceDiagram
    participant Test as Test
    participant SF as StrategyFinder
    participant MD as mockStreamDialer
    participant EPD as errorPacketDialer
    participant CP as CaptivePortalServer (TCP)
    participant TS as httptest.TLSServer (untrusted)

    Test->>SF: NewDialer(ctx, testDomains, configBytes)

    Note over SF: DNS phase
    SF->>EPD: DialPacket(china.cn:53 / ns1.tic.ir:53 / tmcell.tm:53)
    EPD-->>SF: error(dial DNS resolver failed)

    SF->>MD: DialStream(captive-portal.badssl.com:443)
    MD->>CP: DialStream(127.0.0.1:PORT)
    CP-->>MD: accept + close
    MD-->>SF: conn then EOF on TLS wrap

    SF->>MD: DialStream(mitm-software.badssl.com:443)
    MD->>TS: DialStream(127.0.0.1:PORT)
    TS-->>MD: TCP conn
    MD-->>SF: conn (TLS fails - untrusted cert)

    Note over SF: TLS strategy phase
    SF->>MD: DialStream(www.example.com:443)
    MD-->>SF: error (all strategies fail)

    Note over SF: Fallback phase
    SF->>MD: DialStream(1.2.3.4:9999) SS proxy
    MD-->>SF: error
    SF->>SF: error parser returns failed to start dialer
    SF->>MD: DialStream(192.168.1.10:1080) socks5
    MD-->>SF: error

    SF-->>Test: error(could not find a working fallback: all tests failed)

Loading

%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
sequenceDiagram
    participant Test as Test
    participant SF as StrategyFinder
    participant MD as mockStreamDialer
    participant EPD as errorPacketDialer
    participant CP as CaptivePortalServer (TCP)
    participant TS as httptest.TLSServer (untrusted)

    Test->>SF: NewDialer(ctx, testDomains, configBytes)

    Note over SF: DNS phase
    SF->>EPD: DialPacket(china.cn:53 / ns1.tic.ir:53 / tmcell.tm:53)
    EPD-->>SF: error(dial DNS resolver failed)

    SF->>MD: DialStream(captive-portal.badssl.com:443)
    MD->>CP: DialStream(127.0.0.1:PORT)
    CP-->>MD: accept + close
    MD-->>SF: conn then EOF on TLS wrap

    SF->>MD: DialStream(mitm-software.badssl.com:443)
    MD->>TS: DialStream(127.0.0.1:PORT)
    TS-->>MD: TCP conn
    MD-->>SF: conn (TLS fails - untrusted cert)

    Note over SF: TLS strategy phase
    SF->>MD: DialStream(www.example.com:443)
    MD-->>SF: error (all strategies fail)

    Note over SF: Fallback phase
    SF->>MD: DialStream(1.2.3.4:9999) SS proxy
    MD-->>SF: error
    SF->>SF: error parser returns failed to start dialer
    SF->>MD: DialStream(192.168.1.10:1080) socks5
    MD-->>SF: error

    SF-->>Test: error(could not find a working fallback: all tests failed)

Loading

Comments Outside Diff (1)

1. transport/tls/stream_dialer_test.go, line 25-28 (link)

   io and log are inserted after math/big, but alphabetically (i < l < m) they should come before it. goimports would reorder them, which can cause noisy diffs or CI failures if an import-lint check is enforced.

   Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!

_{Reviews (1): Last reviewed commit: "test: mock StrategyFinder dialers in sma..." | Re-trigger Greptile}

[ohnorobo]

thank you for the flakiness fix!