Struct Overrides 

pub struct Overrides {

    pub degrade_health: bool,
    pub health_503: bool,
    pub force_unauthorized: bool,
    pub force_not_found: bool,
    pub force_server_error: bool,
    pub force_empty_evaluation: bool,
    pub force_empty_regime: bool,
    pub force_regime_error_envelope: bool,
    pub force_approaching_not_found: bool,
    pub force_stale_risk_equity: bool,
    pub transient_fail_count: u32,
    pub rate_limit_count: u32,
    pub rate_limit_retry_after: Option<String>,
    pub version: Option<String>,
    pub ws_drop_once: bool,
    pub operator_label: Option<String>,
    pub operator_version: u64,
    pub auto_toggle_echo_state: Option<bool>,
    pub auto_toggle_reason: Option<String>,
    pub force_simulated: bool,
    pub post_transient_fail: bool,
    pub post_server_error: bool,
}

Overrides the test can inject to simulate engine states.

Fields

degrade_health: bool

Force /health status to "degraded" with a custom component.

health_503: bool

Return 503 on /health (simulate overloaded engine).

force_unauthorized: bool

Return 401 on every typed GET endpoint other than / and /health. Exercises [HttpClient]’s auth-error mapping path (HttpError::Unauthorized). The version probe and health surface stay open because the CLI uses them during doctor runs before auth is wired.

force_not_found: bool

Return 404 on every typed GET endpoint (same scope as Self::force_unauthorized). Tests [HttpError::NotFound] mapping and the client’s missing-endpoint log behavior.

force_server_error: bool

Return 500 on every typed GET endpoint. Non-retryable — asserts that the client does not double-call on a server error that isn’t 502/503/504.

force_empty_evaluation: bool

Return a degenerate-but-valid 200 on /evaluate/{coin} — the JSON decodes, but layers is empty and direction is absent. Exercises the dispatcher’s empty-verdict guard (evaluate_cmd must emit an alert + dismiss stale overlays instead of opening an empty verdict card). Does not affect any other endpoint.

force_empty_regime: bool

Return {} (HTTP 200) on /regime. Matches a real production failure mode where the engine exposes the endpoint but never populates a payload. The dispatcher must alert the operator instead of rendering a row of em-dashes that looks like data.

force_regime_error_envelope: bool

Return {"error": "<msg>"} (HTTP 200) on /regime. Matches the engine’s “coin not found” envelope on ?coin=.... The dispatcher must surface the embedded error as an alert.

force_approaching_not_found: bool

Return 404 on /approaching. Matches older engine builds that predate the endpoint. The dispatcher must detect the NotFound and emit an explanatory alert instead of the raw "not found: /approaching" error-display.

force_stale_risk_equity: bool

Return a /risk payload where account_value > peak_equity (mathematically impossible by definition — peak is monotonic max of equity). Mirrors a real production drift where the engine kept writing risk.json with a stale equity number that no live code path refreshed while the portfolio snapshot was fresh. The dispatcher must surface the contradiction instead of rendering a confident (but wrong) drawdown percent.

transient_fail_count: u32

How many further requests should respond with a transient 503 before the real handler runs. Decremented atomically per matched request. Used to verify the retry-once policy (HttpClient::get_json) recovers when the first attempt fails with 503 and the second succeeds. Setting this to >= 2 lets the test observe the retry limit: after one retry, the second failure surfaces as HttpError::Status.

rate_limit_count: u32

How many further requests should respond with a 429 Too Many Requests before the real handler runs. Sister field to Self::transient_fail_count; separated so a test can pin engine-429 behavior without also exercising the transient-retry code path.

When this fires, the response body is empty and the Retry-After header carries Self::rate_limit_retry_after (or a sensible default when unset). The CLI’s HttpClient parses the header, refunds the local bucket, and surfaces HttpError::RateBudgetExhausted { origin: Engine429, .. }.

rate_limit_retry_after: Option<String>

Value placed in the Retry-After header on every injected 429. Accepts any string the real engine might emit — plain integer seconds ("30") or an RFC-7231 IMF-fixdate ("Fri, 31 Dec 1999 23:59:59 GMT"). When None (default), the header carries "1" so tests inspecting the client’s parsed duration see an unambiguous 1 s rather than having to reason about a missing header’s fallback.

version: Option<String>

Custom version string for GET /.

ws_drop_once: bool

Cause the /ws handler to immediately close the connection after accepting the upgrade, exercising the subscriber’s reconnect path. Resets to false automatically after one drop so a test can: set → wait for drop → unset → verify reconnect succeeds.

operator_label: Option<String>

Operator-state label the /operator/state endpoint reports. Defaults to "steady" when unset. Valid values match zero_operator_state::Label snake-case: fresh, steady, elevated, tilt, fatigued, recovery.

operator_version: u64

Monotonic version bumped on each change to operator_label in tests that want to exercise the widget’s version-skip logic. Auto-increments when tests flip the label via with_overrides.

auto_toggle_echo_state: Option<bool>

Engine-side /auto/toggle state the mock echoes back to the next POST /auto/toggle caller. Tests asserting the “engine refuses the flip” path pre-set this to a value that differs from the request, so the response state reflects the engine’s truth rather than the caller’s wish. None means “mirror the request” (happy path).

auto_toggle_reason: Option<String>

Optional reason string the mock returns alongside auto_toggle_echo_state — used to pin the refusal path (e.g. "operator state is TILT"). Emitted verbatim.

force_simulated: bool

When set, every POST /execute and POST /auto/toggle response carries "simulated": true regardless of the X-Zero-Mode header the client sent. Used by tests that want to assert the client surfaces the engine’s truth rather than locally inferring paper from its own --paper flag. In production the engine flips this based on the inbound header; the mock lets tests drive either path.

post_transient_fail: bool

When set, POST /execute and POST /auto/toggle return a single 503. Verifies that no silent retry fires on the no-retry POST surface — the caller sees exactly one upstream request with a typed HttpError::Status back.

post_server_error: bool

When set, POST /execute returns 500. Same intent as Self::post_transient_fail but for a non-retryable status; belt-and-suspenders against any future change to is_retryable accidentally catching the 500 family.

Trait Implementations

impl Clone for Overrides

fn clone(&self) -> Overrides

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Overrides

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Overrides

fn default() -> Overrides

Returns the “default value” for a type.