# Testing In tests you don't want a live edge or a real API key. Configure Shipeasy in test mode with `ConfigureForTesting` (or `ConfigureForOffline`), then read the seeded values through the ordinary `NewClient(user)`. Both are drop-in siblings of `Configure` that do **zero network, ever** — no api key needed — and they **replace** any previous configuration, so a test suite can reconfigure freely between cases. ## `ConfigureForTesting` — seed the values by hand ```go func TestCheckout(t *testing.T) { shipeasy.ConfigureForTesting(shipeasy.TestOptions{ Flags: map[string]bool{"new_checkout": true}, Configs: map[string]any{"billing_copy": map[string]any{"cta": "Buy now"}}, Experiments: map[string]shipeasy.ExperimentOverride{ "checkout_button": {Group: "treatment", Params: map[string]any{"color": "green"}}, }, }) c := shipeasy.NewClient(shipeasy.User{"user_id": "u_123"}) // bind once if !c.GetFlag("new_checkout") { t.Fatal("expected new_checkout on") } if r := c.GetExperiment("checkout_button", nil); r.Group != "treatment" { t.Fatalf("got group %q", r.Group) } } ``` `TestOptions` fields are all optional: | Field | Type | Effect | | --- | --- | --- | | `Flags` | `map[string]bool` | forced `GetFlag` results | | `Configs` | `map[string]any` | forced `GetConfig` results | | `Experiments` | `map[string]ExperimentOverride` | forced enrolments (`Group` + `Params`) | | `Attributes` | `func(any) User` | same transform as `Configure` (default identity) | `Track` and `LogExposure` are no-ops in test mode — they never hit the network. ## On-the-spot overrides The package-level `Override*` helpers force a single value on top of whatever the current configuration set up. They win over everything until `ClearOverrides`: ```go shipeasy.OverrideFlag("new_checkout", true) // force GetFlag → true shipeasy.OverrideConfig("billing_copy", "Buy now") // force GetConfig → ("Buy now", true) shipeasy.OverrideExperiment("checkout_button", "treatment", map[string]any{"color": "green"}) // ... assertions ... shipeasy.ClearOverrides() // reset between cases ``` | Helper | Effect | | --- | --- | | `OverrideFlag(name, bool)` | force `GetFlag(name)` to that value | | `OverrideConfig(name, value)` | force `GetConfig(name)` → `(value, true)` | | `OverrideExperiment(name, group, params)` | force enrolment with `group` / `params` | | `ClearOverrides()` | drop every flag/config/experiment override | Under `ConfigureForTesting` there is no blob beneath, so `ClearOverrides` reverts everything (including the `TestOptions` seed) to empty-blob defaults. Under `ConfigureForOffline` the snapshot remains and evaluations revert to it. ## `ConfigureForOffline` — evaluate the REAL rules from a snapshot `ConfigureForOffline` evaluates the **real** evaluator against a captured snapshot of the edge blobs — still zero network. Provide exactly one source: an in-memory `Snapshot`, or a `Path` to a JSON file. The `Flags` / `Configs` / `Experiments` overrides layer on top. ```go // From a JSON file: shipeasy.ConfigureForOffline(shipeasy.OfflineOptions{Path: "shipeasy-snapshot.json"}) // Or from in-memory parsed blobs: shipeasy.ConfigureForOffline(shipeasy.OfflineOptions{ Snapshot: &shipeasy.Snapshot{Flags: flagsBody, Experiments: experimentsBody}, }) c := shipeasy.NewClient(shipeasy.User{"user_id": "u_123"}) on := c.GetFlag("new_checkout") // runs the real rollout/targeting evaluator _ = on ``` `ConfigureForOffline` returns an error only when reading/parsing a `Path` snapshot fails. ### Snapshot file format The file is JSON of the shape `{ "flags": , "experiments": }`. A minimal but complete, valid snapshot — `new_checkout` rolled out to 10% of users: ```json { "flags": { "version": 1, "plan": "pro", "gates": { "new_checkout": { "rules": [], "rolloutPct": 1000, "salt": "s", "enabled": 1 } }, "configs": {}, "killswitches": {} }, "experiments": { "version": 1, "universes": {}, "experiments": {} } } ``` `rolloutPct` is in **basis points**: `10000` = 100%, `1000` = 10%, `0` = off. A gate object is `{ "rules": [...], "rolloutPct": , "salt": "", "enabled": 0|1 }`.