Class: Shipeasy::Engine

Inherits:
Object
  • Object
show all
Defined in:
lib/shipeasy/engine.rb

Overview

The heavyweight engine: owns the api key, HTTP transport, the blob cache, the background poll timer, init/init_once, local overrides, track, and see()/default-client wiring. Was ‘Shipeasy::SDK::FlagsClient` before 2.0; renamed to a clean top-level `Shipeasy::Engine` when the lightweight user-bound `Shipeasy::Client` became the primary front door.

Most apps never construct an Engine directly — ‘Shipeasy.configure { … }` builds and registers the one global engine for you. Construct one explicitly only for advanced/serverless flows (multiple keys, offline snapshots).

Defined Under Namespace

Classes: FlagDetail

Constant Summary collapse

Eval =

Internal collaborators still live under Shipeasy::SDK; alias them so the body below can keep referring to them unqualified after the class moved out from under the SDK namespace.

Shipeasy::SDK::Eval
Telemetry = 
Shipeasy::SDK::Telemetry
AnonId = 
Shipeasy::SDK::AnonId
See = 
Shipeasy::SDK::See
DEFAULT_BASE_URL = 
"https://edge.shipeasy.dev"
DEFAULT_CDN_BASE =

CDN origin serving the static loader scripts (/sdk/bootstrap.js, /sdk/i18n/loader.js) — distinct from the edge API the blobs are fetched from.

"https://cdn.shipeasy.ai"
REASON_CLIENT_NOT_READY =

Reason constants for FlagDetail#reason / get_flag_detail.

"CLIENT_NOT_READY"
REASON_FLAG_NOT_FOUND =

no blob fetched/loaded yet

"FLAG_NOT_FOUND"
REASON_OFF =

blob present, gate absent

"OFF"
REASON_OVERRIDE =

gate present but disabled/killed

"OVERRIDE"
REASON_RULE_MATCH =

answered by a local override

"RULE_MATCH"
REASON_DEFAULT =

evaluated true

"DEFAULT"

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(api_key:, base_url: nil, env: "prod", disable_telemetry: false, telemetry_url: nil, test_mode: false, private_attributes: nil, sticky_store: nil) ⇒ Engine

Returns a new instance of Engine.



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# File 'lib/shipeasy/engine.rb', line 36

def initialize(api_key:, base_url: nil, env: "prod", disable_telemetry: false, telemetry_url: nil, test_mode: false, private_attributes: nil, sticky_store: nil)
  @api_key     = api_key
  @base_url    = (base_url || DEFAULT_BASE_URL).chomp("/")
  # Read-env tag. Used by telemetry below and stamped onto see() error
  # events so reports are attributable to an environment.
  @env         = env
  # Attribute names usable for targeting but stripped from every outbound
  # /collect payload (LD/Statsig privateAttributes). The server evaluates
  # locally so private attrs never leave for evaluation; the only egress is
  # track(), where the listed keys are dropped from the props bag.
  @private_attributes = (private_attributes || []).map(&:to_s)
  # Pluggable sticky-bucketing store (doc 20 §2). Absent ⇒ deterministic.
  # Threaded into get_experiment so an enrolled unit locks to its first
  # assigned variant. Built-in: InMemoryStickyStore.
  @sticky_store = sticky_store
  # Test mode: no network, ever. init/init_once/track become no-ops and
  # evaluation answers come purely from local overrides. Built via the
  # Engine.for_testing factory; see clear_overrides / override_*.
  @test_mode   = test_mode
  # Per-evaluation usage telemetry. ON by default; pass
  # disable_telemetry: true to opt out. See telemetry.rb.
  @telemetry = Telemetry.new(
    endpoint: telemetry_url || Telemetry::DEFAULT_TELEMETRY_URL,
    sdk_key: api_key,
    side: "server",
    env: env,
    disabled: disable_telemetry,
  )
  @flags_blob  = nil
  @exps_blob   = nil
  @flags_etag  = nil
  @exps_etag   = nil
  @poll_interval = 30
  @mutex       = Mutex.new
  @timer       = nil
  @initialized = false
  # Statsig-style local overrides. Keyed by resource name; an override,
  # when present, short-circuits the corresponding getter. Usable on any
  # client (test or live) for deterministic tests / local development.
  @flag_overrides   = {}
  @config_overrides = {}
  @exp_overrides    = {}
  # Change listeners — fired after a background poll returns NEW data
  # (HTTP 200, not 304). Never fired in test/offline mode. Guarded by
  # @mutex; see on_change / notify_change.
  @change_listeners = []
  # see() structured error reporting. Per-process spam guard, bound here so
  # repeated reports of the same issue collapse to one send. See see.rb.
  @see_limiter = See::Limiter.new
  # Register as the default client backing the module-level Shipeasy::SDK
  # .see/.see_violation funcs (last constructed wins — the server-SDK
  # analog of TS's shipeasy({key}) configure call).
  Shipeasy::SDK.set_default_client(self)
end

Class Method Details

.for_testing(env: "prod") ⇒ Object

Build a no-network, immediately-usable client for tests. Telemetry is disabled, init/init_once/track are no-ops (never fetch), and no api_key is required. Seed it with override_flag / override_config / override_experiment, then call the normal getters.



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# File 'lib/shipeasy/engine.rb', line 95

def self.for_testing(env: "prod")
  new(
    api_key: "test",
    env: env,
    disable_telemetry: true,
    test_mode: true,
  )
end

.from_file(path, env: "prod") ⇒ Object

Build an offline client from a JSON snapshot file. The file holds the raw response bodies of the two SDK endpoints under “flags” and “experiments” keys:

{ "flags": <body of /sdk/flags>, "experiments": <body of /sdk/experiments> }

The returned client does ZERO network (reuses test_mode plumbing: init/init_once/track are no-ops, telemetry off) but, unlike a bare for_testing client, runs the REAL evaluator against the loaded blobs. Local overrides still apply on top. Handy for CI, air-gapped runs, and reproducing a production decision from a captured blob.



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# File 'lib/shipeasy/engine.rb', line 115

def self.from_file(path, env: "prod")
  data = JSON.parse(File.read(path))
  from_snapshot(flags: data["flags"], experiments: data["experiments"], env: env)
end

.from_snapshot(flags: nil, experiments: nil, env: "prod") ⇒ Object

Build an offline client directly from already-parsed blobs (same shape as the /sdk/flags and /sdk/experiments response bodies). See from_file.



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# File 'lib/shipeasy/engine.rb', line 122

def self.from_snapshot(flags: nil, experiments: nil, env: "prod")
  client = for_testing(env: env)
  client.send(:load_snapshot, flags, experiments)
  client
end

Instance Method Details

#bind_attributes(user) ⇒ Object

Public hook for the bound Shipeasy::Client: normalise an attribute hash and apply the request-scoped anonymous_id merge ONCE, at Client construction, exactly as every per-call getter does internally.



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# File 'lib/shipeasy/engine.rb', line 297

def bind_attributes(user)
  with_anon_id(user)
end

#bootstrap_script_tag(user, anon_id: nil, i18n_profile: "en:prod", base_url: nil) ⇒ Object

Return the cross-platform SSR bootstrap <script> tag for a request: se-bootstrap.js reads its data-* attributes and hydrates window.__SE_BOOTSTRAP (and writes the anon cookie). No key is embedded.



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# File 'lib/shipeasy/engine.rb', line 356

def bootstrap_script_tag(user, anon_id: nil, i18n_profile: "en:prod", base_url: nil)
  payload = evaluate(user)
  base = cdn_base(base_url)
  attrs = [
    "data-se-bootstrap",
    attr("data-flags", JSON.generate(payload["flags"])),
    attr("data-configs", JSON.generate(payload["configs"])),
    attr("data-experiments", JSON.generate(payload["experiments"])),
    attr("data-killswitches", JSON.generate(payload["killswitches"])),
    attr("data-i18n-profile", i18n_profile || "en:prod"),
    attr("data-api-url", base),
  ]
  attrs << attr("data-anon-id", anon_id) if anon_id && !anon_id.empty?
  %(<script src="#{CGI.escapeHTML("#{base}/sdk/bootstrap.js")}" #{attrs.join(' ')}></script>)
end

#clear_overrides ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 164

def clear_overrides
  @mutex.synchronize do
    @flag_overrides.clear
    @config_overrides.clear
    @exp_overrides.clear
  end
  self
end

#control_flow_exception(err) ⇒ Object Also known as: controlFlowException

Mark an exception as expected control flow — reports nothing. Returns a ‘.because(reason)` tail (with optional `.extras` for local debug only).



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# File 'lib/shipeasy/engine.rb', line 454

def control_flow_exception(err)
  See::ControlFlowChain.new(err)
end

#destroy ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 184

def destroy
  @timer&.kill
  @timer = nil
end

#evaluate(user) ⇒ Object

Batch-evaluate every loaded gate, config and experiment for user into a bootstrap payload (+{ “flags” => …, “configs” => …, “experiments”

> …, “killswitches” => … }+) keyed to match the browser SDK’s

window.__SE_BOOTSTRAP shape. Local overrides win. Killswitches are folded into per-gate evaluation, so the standalone killswitches map is empty for this SDK. No telemetry (a batch evaluate is not a per-flag exposure).



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# File 'lib/shipeasy/engine.rb', line 322

def evaluate(user)
  u = with_anon_id(user)
  flags_blob, exps_blob, flag_ov, config_ov, exp_ov, sticky = @mutex.synchronize do
    [@flags_blob, @exps_blob, @flag_overrides.dup, @config_overrides.dup,
     @exp_overrides.dup, @sticky_store]
  end

  flags = {}
  (flags_blob&.dig("gates") || {}).each do |name, gate|
    flags[name] = flag_ov.key?(name) ? flag_ov[name] : Eval.eval_gate(gate, u)
  end

  configs = {}
  (flags_blob&.dig("configs") || {}).each do |name, entry|
    configs[name] = config_ov.key?(name) ? config_ov[name] : entry["value"]
  end

  experiments = {}
  (exps_blob&.dig("experiments") || {}).each do |name, exp|
    if exp_ov.key?(name)
      ov = exp_ov[name]
      experiments[name] = { "inExperiment" => true, "group" => ov[:group], "params" => ov[:params] }
      next
    end
    r = Eval.eval_experiment(exp, flags_blob, exps_blob, u, exp_name: name, sticky_store: sticky)
    experiments[name] = { "inExperiment" => r.in_experiment, "group" => r.group, "params" => r.params }
  end

  { "flags" => flags, "configs" => configs, "experiments" => experiments, "killswitches" => {} }
end

#get_config(name, decode = nil, default: nil) ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 240

def get_config(name, decode = nil, default: nil)
  key = name.to_s
  has_override, override = @mutex.synchronize do
    [@config_overrides.key?(key), @config_overrides[key]]
  end
  if has_override
    return decode ? decode.call(override) : override
  end

  @telemetry.emit("config", name)
  entry = @mutex.synchronize { @flags_blob&.dig("configs", name) }
  return default unless entry
  value = entry["value"]
  decode ? decode.call(value) : value
end

#get_experiment(name, user, default_params, decode = nil) ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 256

def get_experiment(name, user, default_params, decode = nil)
  key = name.to_s
  override = @mutex.synchronize { @exp_overrides[key] }
  if override
    params = override[:params]
    params = decode.call(params) if decode
    return Eval::ExperimentResult.new(
      in_experiment: true,
      group: override[:group],
      params: params,
    )
  end

  @telemetry.emit("experiment", name)
  flags_blob, exps_blob = @mutex.synchronize { [@flags_blob, @exps_blob] }
  exp = exps_blob&.dig("experiments", name)
  result = Eval.eval_experiment(
    exp, flags_blob, exps_blob, with_anon_id(user),
    exp_name: name.to_s, sticky_store: @sticky_store,
  )
  result.params ||= default_params

  if result.in_experiment && decode
    begin
      result = Eval::ExperimentResult.new(
        in_experiment: true,
        group: result.group,
        params: decode.call(result.params),
      )
    rescue => e
      warn "[shipeasy] get_experiment('#{name}') decode failed: #{e.message}"
      return Eval::ExperimentResult.new(in_experiment: false, group: "control", params: default_params)
    end
  end

  result
end

#get_flag(name, user, default: false) ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 231

def get_flag(name, user, default: false)
  detail = get_flag_detail(name, user)
  if detail.reason == REASON_CLIENT_NOT_READY || detail.reason == REASON_FLAG_NOT_FOUND
    default
  else
    detail.value
  end
end

#get_flag_detail(name, user) ⇒ Object

Evaluate a flag and return why. Telemetry (“gate” beacon) is emitted exactly once here (steps 2–5), never on the OVERRIDE short-circuit.



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# File 'lib/shipeasy/engine.rb', line 203

def get_flag_detail(name, user)
  key = name.to_s

  # 1. Override short-circuits before any telemetry (mirrors get_config).
  override = @mutex.synchronize { @flag_overrides[key] if @flag_overrides.key?(key) }
  return FlagDetail.new(value: override, reason: REASON_OVERRIDE) unless override.nil?

  @telemetry.emit("gate", name)

  flags_blob, gate = @mutex.synchronize { [@flags_blob, @flags_blob&.dig("gates", name)] }

  # 2. Not initialized — no blob fetched or loaded yet.
  return FlagDetail.new(value: false, reason: REASON_CLIENT_NOT_READY) if flags_blob.nil?

  # 3. Blob present but this gate isn't in it.
  return FlagDetail.new(value: false, reason: REASON_FLAG_NOT_FOUND) unless gate

  # 4. Gate present but disabled (or killswitched) — eval_gate would also
  #    return false here, but the reason is OFF, not a rollout DEFAULT.
  if Eval.enabled?(gate["killswitch"]) || !Eval.enabled?(gate["enabled"])
    return FlagDetail.new(value: false, reason: REASON_OFF)
  end

  # 5. Run the canonical evaluator; reason follows the boolean result.
  result = Eval.eval_gate(gate, with_anon_id(user))
  FlagDetail.new(value: result, reason: result ? REASON_RULE_MATCH : REASON_DEFAULT)
end

#get_killswitch(name, switch_key = nil) ⇒ Object

Read a killswitch from the cached flags blob. Without switch_key, returns true when the whole killswitch is killed. With switch_key, returns true when that specific per-key switch is on. Unknown killswitches / switches return false. Not user-scoped.



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# File 'lib/shipeasy/engine.rb', line 305

def get_killswitch(name, switch_key = nil)
  @telemetry.emit("ks", name)
  ks = @mutex.synchronize { @flags_blob&.dig("killswitches", name.to_s) }
  return false unless ks
  if switch_key.nil?
    Eval.enabled?(ks["killed"])
  else
    Eval.enabled?(ks.dig("switches", switch_key.to_s))
  end
end

#i18n_script_tag(client_key, profile: "en:prod", base_url: nil) ⇒ Object

Return the i18n loader <script> tag (framework-agnostic; the Rails view helper Shipeasy::I18n::ViewHelpers#i18n_script_tag is separate). The loader fetches translations for the profile using the PUBLIC client key.



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# File 'lib/shipeasy/engine.rb', line 375

def i18n_script_tag(client_key, profile: "en:prod", base_url: nil)
  base = cdn_base(base_url)
  %(<script src="#{CGI.escapeHTML("#{base}/sdk/i18n/loader.js")}" ) +
    %(#{attr('data-key', client_key)} #{attr('data-profile', profile || 'en:prod')}></script>)
end

#init ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 128

def init
  return if @test_mode
  fetch_all
  @initialized = true
  start_poll
end

#init_once ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 135

def init_once
  return if @test_mode
  return if @initialized
  fetch_all
  @initialized = true
end

#log_exposure(user_or_user_id, experiment_name) ⇒ Object

Emit an exposure event for an experiment at the server-side decision point (parity with the browser’s auto-exposure). The server is stateless and never auto-logs, so call this when you actually present the treatment. Re-evaluates the experiment for the user (a bare user_id string is wrapped as { “user_id” => id }); if enrolled, POSTs a single exposure to /collect. No-op in test mode or when the user isn’t enrolled.



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# File 'lib/shipeasy/engine.rb', line 409

def log_exposure(user_or_user_id, experiment_name)
  return if @test_mode

  user = user_or_user_id.is_a?(Hash) ? user_or_user_id : { "user_id" => user_or_user_id.to_s }
  result = get_experiment(experiment_name, user, {})
  return unless result.in_experiment

  u = user.transform_keys(&:to_s)
  payload = JSON.generate({
    events: [{
      type: "exposure",
      experiment: experiment_name.to_s,
      group: result.group,
      user_id: (u["user_id"] || u["anonymous_id"]).to_s,
      ts: (Time.now.to_f * 1000).to_i,
    }],
  })

  Thread.new do
    post("/collect", payload)
  rescue => e
    warn "[shipeasy] log_exposure failed: #{e.message}"
  end
end

#on_change(callable = nil, &block) ⇒ Object

Register a listener fired after a background poll fetches NEW flag/config data (HTTP 200, not 304). Accepts either a block or any callable (an object responding to #call). Returns an unsubscribe proc — call it to remove the listener. Never fires in test/offline mode (no poll thread).

Raises:

  • (ArgumentError) 


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# File 'lib/shipeasy/engine.rb', line 177

def on_change(callable = nil, &block)
  listener = callable || block
  raise ArgumentError, "on_change requires a block or callable" unless listener.respond_to?(:call)
  @mutex.synchronize { @change_listeners << listener }
  proc { @mutex.synchronize { @change_listeners.delete(listener) } }
end

#override_config(name, value) ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 152

def override_config(name, value)
  @mutex.synchronize { @config_overrides[name.to_s] = value }
  self
end

#override_experiment(name, group, params) ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 157

def override_experiment(name, group, params)
  @mutex.synchronize do
    @exp_overrides[name.to_s] = { group: group, params: params }
  end
  self
end

#override_flag(name, value) ⇒ Object

— Local overrides ————————————————- An override wins over the fetched blob in the matching getter. Setters are mutex-guarded so they’re safe to call alongside background polling on a live client.



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# File 'lib/shipeasy/engine.rb', line 147

def override_flag(name, value)
  @mutex.synchronize { @flag_overrides[name.to_s] = (value ? true : false) }
  self
end

#see(problem) ⇒ Object

Report a caught exception (or thrown non-exception). Fire-and-forget; never blocks or throws into the request path. Terminate with ‘.to(outcome)`:

client.see(e).causes_the("checkout").to("use cached prices")



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# File 'lib/shipeasy/engine.rb', line 441

def see(problem)
  See::Chain.new(problem, method(:dispatch_see))
end

#see_violation(name) ⇒ Object Also known as: seeViolation

Report a non-exception problem. The name is a stable fingerprint key —put variable data in ‘.extras`, never in the name.



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# File 'lib/shipeasy/engine.rb', line 447

def see_violation(name)
  See::Chain.new(See::Violation.new(name), method(:dispatch_see))
end

#track(user_id, event_name, props = {}) ⇒ Object 



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# File 'lib/shipeasy/engine.rb', line 381

def track(user_id, event_name, props = {})
  return if @test_mode

  safe_props = strip_private(props)

  payload = JSON.generate({
    events: [{
      type: "metric",
      event_name: event_name,
      user_id: user_id.to_s,
      ts: (Time.now.to_f * 1000).to_i,
      **(safe_props.empty? ? {} : { properties: safe_props }),
    }],
  })

  Thread.new do
    post("/collect", payload)
  rescue => e
    warn "[shipeasy] track failed: #{e.message}"
  end
end