Class: Shipeasy::SDK::FlagsClient

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

Defined Under Namespace

Classes: FlagDetail

Constant Summary collapse

DEFAULT_BASE_URL = 
"https://edge.shipeasy.dev"
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) ⇒ FlagsClient

Returns a new instance of FlagsClient.



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# File 'lib/shipeasy/sdk/flags_client.rb', line 14

def initialize(api_key:, base_url: nil, env: "prod", disable_telemetry: false, telemetry_url: nil, test_mode: false)
  @api_key     = api_key
  @base_url    = (base_url || DEFAULT_BASE_URL).chomp("/")
  # Test mode: no network, ever. init/init_once/track become no-ops and
  # evaluation answers come purely from local overrides. Built via the
  # FlagsClient.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 = []
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/sdk/flags_client.rb', line 54

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/sdk/flags_client.rb', line 74

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/sdk/flags_client.rb', line 81

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

#clear_overrides ⇒ Object 



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# File 'lib/shipeasy/sdk/flags_client.rb', line 123

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

#destroy ⇒ Object 



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# File 'lib/shipeasy/sdk/flags_client.rb', line 143

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

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



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# File 'lib/shipeasy/sdk/flags_client.rb', line 199

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/sdk/flags_client.rb', line 215

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))
  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/sdk/flags_client.rb', line 190

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/sdk/flags_client.rb', line 162

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

#init ⇒ Object 



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# File 'lib/shipeasy/sdk/flags_client.rb', line 87

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

#init_once ⇒ Object 



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# File 'lib/shipeasy/sdk/flags_client.rb', line 94

def init_once
  return if @test_mode
  return if @initialized
  fetch_all
  @initialized = true
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/sdk/flags_client.rb', line 136

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/sdk/flags_client.rb', line 111

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/sdk/flags_client.rb', line 116

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/sdk/flags_client.rb', line 106

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

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



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# File 'lib/shipeasy/sdk/flags_client.rb', line 250

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

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

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