fvictorio
6 years ago
parent
04d734fb1f
commit
616658adbf
@ -0,0 +1,131 @@ |
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defmodule Explorer.KnownTokens do |
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@moduledoc """ |
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Local cache for known tokens addresses. This fetches and exposes a mapping from a token symbol to the known contract |
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address for the token with that symbol. This data can be consumed through the Market module. |
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Data is updated every 1 hour. |
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""" |
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|
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use GenServer |
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require Logger |
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alias Explorer.Chain.Hash |
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alias Explorer.KnownTokens.Source |
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@interval :timer.hours(1) |
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@table_name :known_tokens |
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@impl GenServer |
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def handle_info(:update, state) do |
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Logger.debug(fn -> "Updating cached known tokens" end) |
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fetch_known_tokens() |
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{:noreply, state} |
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end |
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# Callback for successful fetch |
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@impl GenServer |
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def handle_info({_ref, {:ok, addresses}}, state) do |
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if store() == :ets do |
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records = Enum.map(addresses, fn x -> {x["symbol"], x["address"]} end) |
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:ets.insert(table_name(), records) |
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end |
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{:noreply, state} |
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end |
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|
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# Callback for errored fetch |
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@impl GenServer |
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def handle_info({_ref, {:error, reason}}, state) do |
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Logger.warn(fn -> "Failed to get known tokens with reason '#{reason}'." end) |
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fetch_known_tokens() |
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{:noreply, state} |
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end |
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# Callback that a monitored process has shutdown |
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@impl GenServer |
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def handle_info({:DOWN, _, :process, _, _}, state) do |
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{:noreply, state} |
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end |
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@impl GenServer |
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def init(_) do |
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send(self(), :update) |
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:timer.send_interval(@interval, :update) |
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table_opts = [ |
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:set, |
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:named_table, |
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:public, |
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read_concurrency: true |
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] |
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if store() == :ets do |
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:ets.new(table_name(), table_opts) |
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end |
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{:ok, %{}} |
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end |
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def start_link(opts) do |
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GenServer.start_link(__MODULE__, opts, name: __MODULE__) |
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end |
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@doc """ |
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Lists known tokens. |
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""" |
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@spec list :: [{String.t(), Hash.Address.t()}] |
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def list do |
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list_from_store(store()) |
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end |
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@doc """ |
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Returns a specific address from the known tokens by symbol |
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""" |
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@spec lookup(String.t()) :: {:ok, Hash.Address.t()} | :error | nil |
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def lookup(symbol) do |
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if store() == :ets do |
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case :ets.lookup(table_name(), symbol) do |
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[{_symbol, address} | _] -> Hash.Address.cast(address) |
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_ -> nil |
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end |
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end |
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end |
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@doc false |
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@spec table_name() :: atom() |
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def table_name do |
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config(:table_name) || @table_name |
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end |
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@spec config(atom()) :: term |
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defp config(key) do |
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Application.get_env(:explorer, __MODULE__, [])[key] |
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end |
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|
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@spec fetch_known_tokens :: Task.t() |
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defp fetch_known_tokens do |
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Task.Supervisor.async_nolink(Explorer.MarketTaskSupervisor, fn -> |
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Source.fetch_known_tokens() |
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end) |
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end |
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defp list_from_store(:ets) do |
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table_name() |
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|> :ets.tab2list() |
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|> Enum.map(&elem(&1, 1)) |
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|> Enum.map(&Hash.Address.cast/1) |
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|> Enum.sort() |
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end |
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defp list_from_store(_), do: [] |
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defp store do |
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config(:store) || :ets |
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end |
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end |
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@ -0,0 +1,48 @@ |
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defmodule Explorer.KnownTokens.Source do |
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@moduledoc """ |
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Behaviour for fetching list of known tokens. |
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""" |
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alias Explorer.Chain.Hash |
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alias HTTPoison.{Error, Response} |
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@doc """ |
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Fetches known tokens |
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""" |
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@spec fetch_known_tokens() :: {:ok, [Hash.Address.t()]} | {:error, any} |
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def fetch_known_tokens(source \\ known_tokens_source()) do |
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case HTTPoison.get(source.source_url(), headers()) do |
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{:ok, %Response{body: body, status_code: 200}} -> |
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{:ok, decode_json(body)} |
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{:ok, %Response{body: body, status_code: status_code}} when status_code in 400..499 -> |
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{:error, decode_json(body)["error"]} |
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{:error, %Error{reason: reason}} -> |
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{:error, reason} |
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end |
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end |
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@doc """ |
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Url for querying the list of known tokens. |
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""" |
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@callback source_url() :: String.t() |
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def headers do |
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[{"Content-Type", "application/json"}] |
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end |
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def decode_json(data) do |
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Jason.decode!(data) |
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end |
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@spec known_tokens_source() :: module() |
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defp known_tokens_source do |
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config(:source) || Explorer.KnownTokens.Source.MyEtherWallet |
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end |
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@spec config(atom()) :: term |
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defp config(key) do |
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Application.get_env(:explorer, __MODULE__, [])[key] |
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end |
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end |
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@ -0,0 +1,14 @@ |
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defmodule Explorer.KnownTokens.Source.MyEtherWallet do |
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@moduledoc """ |
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Adapter for fetching known tokens from MyEtherWallet's GitHub |
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""" |
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alias Explorer.KnownTokens.Source |
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@behaviour Source |
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@impl Source |
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def source_url do |
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"https://raw.githubusercontent.com/kvhnuke/etherwallet/mercury/app/scripts/tokens/ethTokens.json" |
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end |
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end |
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@ -0,0 +1,131 @@ |
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defmodule Explorer.KnownTokensTest do |
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use ExUnit.Case, async: false |
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import Mox |
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alias Plug.Conn |
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alias Explorer.Chain.Hash |
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alias Explorer.KnownTokens |
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alias Explorer.KnownTokens.Source.TestSource |
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@moduletag :capture_log |
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setup :verify_on_exit! |
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setup do |
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set_mox_global() |
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# Use TestSource mock and ets table for this test set |
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source_configuration = Application.get_env(:explorer, Explorer.KnownTokens.Source) |
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known_tokens_configuration = Application.get_env(:explorer, Explorer.KnownTokens) |
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Application.put_env(:explorer, Explorer.KnownTokens.Source, source: TestSource) |
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Application.put_env(:explorer, Explorer.KnownTokens, table_name: :known_tokens) |
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on_exit(fn -> |
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Application.put_env(:explorer, Explorer.KnownTokens.Source, source_configuration) |
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Application.put_env(:explorer, Explorer.KnownTokens, known_tokens_configuration) |
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end) |
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end |
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test "init" do |
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assert :ets.info(KnownTokens.table_name()) == :undefined |
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assert {:ok, %{}} == KnownTokens.init([]) |
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assert_received :update |
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table = :ets.info(KnownTokens.table_name()) |
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refute table == :undefined |
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assert table[:name] == KnownTokens.table_name() |
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assert table[:named_table] |
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assert table[:read_concurrency] |
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assert table[:type] == :set |
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refute table[:write_concurrency] |
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end |
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test "handle_info with :update" do |
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bypass = Bypass.open() |
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Bypass.expect(bypass, "GET", "/", fn conn -> |
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Conn.resp(conn, 200, ~s([{"symbol": "TEST1","address": "0x0000000000000000000000000000000000000001"}])) |
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end) |
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stub(TestSource, :source_url, fn -> "http://localhost:#{bypass.port}" end) |
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KnownTokens.init([]) |
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state = %{} |
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assert {:noreply, ^state} = KnownTokens.handle_info(:update, state) |
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assert_receive {_, {:ok, [%{"symbol" => "TEST1", "address" => "0x0000000000000000000000000000000000000001"}]}} |
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end |
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describe "ticker fetch task" do |
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setup do |
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KnownTokens.init([]) |
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:ok |
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end |
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test "with successful fetch" do |
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symbol = "TEST2" |
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address = "0x0000000000000000000000000000000000000002" |
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token = %{ |
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"symbol" => symbol, |
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"address" => address |
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} |
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state = %{} |
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assert {:noreply, ^state} = KnownTokens.handle_info({nil, {:ok, [token]}}, state) |
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assert [{"TEST2", "0x0000000000000000000000000000000000000002"}] == :ets.lookup(KnownTokens.table_name(), symbol) |
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end |
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test "with failed fetch" do |
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bypass = Bypass.open() |
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Bypass.expect(bypass, "GET", "/", fn conn -> |
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Conn.resp(conn, 200, "{}") |
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end) |
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stub(TestSource, :source_url, fn -> "http://localhost:#{bypass.port}" end) |
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state = %{} |
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assert {:noreply, ^state} = KnownTokens.handle_info({nil, {:error, "some error"}}, state) |
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assert_receive {_, {:ok, _}} |
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end |
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end |
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test "list/0" do |
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KnownTokens.init([]) |
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known_tokens = [ |
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{"TEST1", "0x0000000000000000000000000000000000000001"}, |
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{"TEST2", "0x0000000000000000000000000000000000000002"} |
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] |
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:ets.insert(KnownTokens.table_name(), known_tokens) |
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expected_tokens = |
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known_tokens |
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|> Enum.map(&elem(&1, 1)) |
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|> Enum.map(&Hash.Address.cast/1) |
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assert expected_tokens == KnownTokens.list() |
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end |
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test "lookup/1" do |
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KnownTokens.init([]) |
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known_tokens = [ |
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{"TEST1", "0x0000000000000000000000000000000000000001"}, |
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{"TEST2", "0x0000000000000000000000000000000000000002"} |
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] |
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:ets.insert(KnownTokens.table_name(), known_tokens) |
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assert Hash.Address.cast("0x0000000000000000000000000000000000000001") == KnownTokens.lookup("TEST1") |
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assert nil == KnownTokens.lookup("nope") |
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end |
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end |
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