feat: add elixir-provider

openfeature/providers/elixir-provider/.credo.exs

@@ -0,0 +1,217 @@
+# This file contains the configuration for Credo and you are probably reading
+# this after creating it with `mix credo.gen.config`.
+#
+# If you find anything wrong or unclear in this file, please report an
+# issue on GitHub: https://github.com/rrrene/credo/issues
+#
+%{
+  #
+  # You can have as many configs as you like in the `configs:` field.
+  configs: [
+    %{
+      #
+      # Run any config using `mix credo -C <name>`. If no config name is given
+      # "default" is used.
+      #
+      name: "default",
+      #
+      # These are the files included in the analysis:
+      files: %{
+        #
+        # You can give explicit globs or simply directories.
+        # In the latter case `**/*.{ex,exs}` will be used.
+        #
+        included: [
+          "lib/",
+          "src/",
+          "test/",
+          "web/",
+          "apps/*/lib/",
+          "apps/*/src/",
+          "apps/*/test/",
+          "apps/*/web/"
+        ],
+        excluded: [~r"/_build/", ~r"/deps/", ~r"/node_modules/"]
+      },
+      #
+      # Load and configure plugins here:
+      #
+      plugins: [],
+      #
+      # If you create your own checks, you must specify the source files for
+      # them here, so they can be loaded by Credo before running the analysis.
+      #
+      requires: [],
+      #
+      # If you want to enforce a style guide and need a more traditional linting
+      # experience, you can change `strict` to `true` below:
+      #
+      strict: false,
+      #
+      # To modify the timeout for parsing files, change this value:
+      #
+      parse_timeout: 5000,
+      #
+      # If you want to use uncolored output by default, you can change `color`
+      # to `false` below:
+      #
+      color: true,
+      #
+      # You can customize the parameters of any check by adding a second element
+      # to the tuple.
+      #
+      # To disable a check put `false` as second element:
+      #
+      #     {Credo.Check.Design.DuplicatedCode, false}
+      #
+      checks: %{
+        enabled: [
+          #
+          ## Consistency Checks
+          #
+          {Credo.Check.Consistency.ExceptionNames, []},
+          {Credo.Check.Consistency.LineEndings, []},
+          {Credo.Check.Consistency.ParameterPatternMatching, []},
+          {Credo.Check.Consistency.SpaceAroundOperators, []},
+          {Credo.Check.Consistency.SpaceInParentheses, []},
+          {Credo.Check.Consistency.TabsOrSpaces, []},
+
+          #
+          ## Design Checks
+          #
+          # You can customize the priority of any check
+          # Priority values are: `low, normal, high, higher`
+          #
+          {Credo.Check.Design.AliasUsage,
+           [priority: :low, if_nested_deeper_than: 2, if_called_more_often_than: 0]},
+          {Credo.Check.Design.TagFIXME, []},
+          # You can also customize the exit_status of each check.
+          # If you don't want TODO comments to cause `mix credo` to fail, just
+          # set this value to 0 (zero).
+          #
+          {Credo.Check.Design.TagTODO, [exit_status: 2]},
+
+          #
+          ## Readability Checks
+          #
+          {Credo.Check.Readability.AliasOrder, []},
+          {Credo.Check.Readability.FunctionNames, []},
+          {Credo.Check.Readability.LargeNumbers, []},
+          {Credo.Check.Readability.MaxLineLength, [priority: :low, max_length: 120]},
+          {Credo.Check.Readability.ModuleAttributeNames, []},
+          {Credo.Check.Readability.ModuleDoc, []},
+          {Credo.Check.Readability.ModuleNames, []},
+          {Credo.Check.Readability.ParenthesesInCondition, []},
+          {Credo.Check.Readability.ParenthesesOnZeroArityDefs, []},
+          {Credo.Check.Readability.PipeIntoAnonymousFunctions, []},
+          {Credo.Check.Readability.PredicateFunctionNames, []},
+          {Credo.Check.Readability.PreferImplicitTry, []},
+          {Credo.Check.Readability.RedundantBlankLines, []},
+          {Credo.Check.Readability.Semicolons, []},
+          {Credo.Check.Readability.SpaceAfterCommas, []},
+          {Credo.Check.Readability.StringSigils, []},
+          {Credo.Check.Readability.TrailingBlankLine, []},
+          {Credo.Check.Readability.TrailingWhiteSpace, []},
+          {Credo.Check.Readability.UnnecessaryAliasExpansion, []},
+          {Credo.Check.Readability.VariableNames, []},
+          {Credo.Check.Readability.WithSingleClause, []},
+
+          #
+          ## Refactoring Opportunities
+          #
+          {Credo.Check.Refactor.Apply, []},
+          {Credo.Check.Refactor.CondStatements, []},
+          {Credo.Check.Refactor.CyclomaticComplexity, []},
+          {Credo.Check.Refactor.FilterCount, []},
+          {Credo.Check.Refactor.FilterFilter, []},
+          {Credo.Check.Refactor.FunctionArity, []},
+          {Credo.Check.Refactor.LongQuoteBlocks, []},
+          {Credo.Check.Refactor.MapJoin, []},
+          {Credo.Check.Refactor.MatchInCondition, []},
+          {Credo.Check.Refactor.NegatedConditionsInUnless, []},
+          {Credo.Check.Refactor.NegatedConditionsWithElse, []},
+          {Credo.Check.Refactor.Nesting, []},
+          {Credo.Check.Refactor.RedundantWithClauseResult, []},
+          {Credo.Check.Refactor.RejectReject, []},
+          {Credo.Check.Refactor.UnlessWithElse, []},
+          {Credo.Check.Refactor.WithClauses, []},
+
+          #
+          ## Warnings
+          #
+          {Credo.Check.Warning.ApplicationConfigInModuleAttribute, []},
+          {Credo.Check.Warning.BoolOperationOnSameValues, []},
+          {Credo.Check.Warning.Dbg, []},
+          {Credo.Check.Warning.ExpensiveEmptyEnumCheck, []},
+          {Credo.Check.Warning.IExPry, []},
+          {Credo.Check.Warning.IoInspect, []},
+          {Credo.Check.Warning.MissedMetadataKeyInLoggerConfig, []},
+          {Credo.Check.Warning.OperationOnSameValues, []},
+          {Credo.Check.Warning.OperationWithConstantResult, []},
+          {Credo.Check.Warning.RaiseInsideRescue, []},
+          {Credo.Check.Warning.SpecWithStruct, []},
+          {Credo.Check.Warning.UnsafeExec, []},
+          {Credo.Check.Warning.UnusedEnumOperation, []},
+          {Credo.Check.Warning.UnusedFileOperation, []},
+          {Credo.Check.Warning.UnusedKeywordOperation, []},
+          {Credo.Check.Warning.UnusedListOperation, []},
+          {Credo.Check.Warning.UnusedPathOperation, []},
+          {Credo.Check.Warning.UnusedRegexOperation, []},
+          {Credo.Check.Warning.UnusedStringOperation, []},
+          {Credo.Check.Warning.UnusedTupleOperation, []},
+          {Credo.Check.Warning.WrongTestFileExtension, []}
+        ],
+        disabled: [
+          #
+          # Checks scheduled for next check update (opt-in for now)
+          {Credo.Check.Refactor.UtcNowTruncate, []},
+
+          #
+          # Controversial and experimental checks (opt-in, just move the check to `:enabled`
+          #   and be sure to use `mix credo --strict` to see low priority checks)
+          #
+          {Credo.Check.Consistency.MultiAliasImportRequireUse, []},
+          {Credo.Check.Consistency.UnusedVariableNames, []},
+          {Credo.Check.Design.DuplicatedCode, []},
+          {Credo.Check.Design.SkipTestWithoutComment, []},
+          {Credo.Check.Readability.AliasAs, []},
+          {Credo.Check.Readability.BlockPipe, []},
+          {Credo.Check.Readability.ImplTrue, []},
+          {Credo.Check.Readability.MultiAlias, []},
+          {Credo.Check.Readability.NestedFunctionCalls, []},
+          {Credo.Check.Readability.OneArityFunctionInPipe, []},
+          {Credo.Check.Readability.OnePipePerLine, []},
+          {Credo.Check.Readability.SeparateAliasRequire, []},
+          {Credo.Check.Readability.SingleFunctionToBlockPipe, []},
+          {Credo.Check.Readability.SinglePipe, []},
+          {Credo.Check.Readability.Specs, []},
+          {Credo.Check.Readability.StrictModuleLayout, []},
+          {Credo.Check.Readability.WithCustomTaggedTuple, []},
+          {Credo.Check.Refactor.ABCSize, []},
+          {Credo.Check.Refactor.AppendSingleItem, []},
+          {Credo.Check.Refactor.DoubleBooleanNegation, []},
+          {Credo.Check.Refactor.FilterReject, []},
+          {Credo.Check.Refactor.IoPuts, []},
+          {Credo.Check.Refactor.MapMap, []},
+          {Credo.Check.Refactor.ModuleDependencies, []},
+          {Credo.Check.Refactor.NegatedIsNil, []},
+          {Credo.Check.Refactor.PassAsyncInTestCases, []},
+          {Credo.Check.Refactor.PipeChainStart, []},
+          {Credo.Check.Refactor.RejectFilter, []},
+          {Credo.Check.Refactor.VariableRebinding, []},
+          {Credo.Check.Warning.LazyLogging, []},
+          {Credo.Check.Warning.LeakyEnvironment, []},
+          {Credo.Check.Warning.MapGetUnsafePass, []},
+          {Credo.Check.Warning.MixEnv, []},
+          {Credo.Check.Warning.UnsafeToAtom, []}
+
+          # {Credo.Check.Refactor.MapInto, []},
+
+          #
+          # Custom checks can be created using `mix credo.gen.check`.
+          #
+        ]
+      }
+    }
+  ]
+}

openfeature/providers/elixir-provider/.formatter.exs

@@ -0,0 +1,4 @@
+# Used by "mix format"
+[
+  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+]

openfeature/providers/elixir-provider/.gitignore

@@ -0,0 +1,28 @@
+# The directory Mix will write compiled artifacts to.
+/_build/
+
+# If you run "mix test --cover", coverage assets end up here.
+/cover/
+
+# The directory Mix downloads your dependencies sources to.
+/deps/
+
+# Where third-party dependencies like ExDoc output generated docs.
+/doc/
+
+# Ignore .fetch files in case you like to edit your project deps locally.
+/.fetch
+
+# If the VM crashes, it generates a dump, let's ignore it too.
+erl_crash.dump
+
+# Also ignore archive artifacts (built via "mix archive.build").
+*.ez
+
+# Ignore package tarball (built via "mix hex.build").
+elixir_provider-*.tar
+
+# Temporary files, for example, from tests.
+/tmp/
+
+.elixir_ls

openfeature/providers/elixir-provider/README.md

@@ -0,0 +1,21 @@
+# ElixirProvider
+
+**TODO: Add description**
+
+## Installation
+
+If [available in Hex](https://hex.pm/docs/publish), the package can be installed
+by adding `elixir_provider` to your list of dependencies in `mix.exs`:
+
+```elixir
+def deps do
+  [
+    {:elixir_provider, "~> 0.1.0"}
+  ]
+end
+```
+
+Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
+and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
+be found at <https://hexdocs.pm/elixir_provider>.
+

openfeature/providers/elixir-provider/config/config.exs

@@ -0,0 +1,7 @@
+import Config
+
+config :elixir_provider,
+  max_wait_time: 5000,
+  hackney_options: [timeout: :infinity, recv_timeout: :infinity]
+
+import_config "#{config_env()}.exs"

openfeature/providers/elixir-provider/config/dev.exs

@@ -0,0 +1 @@
+import Config

openfeature/providers/elixir-provider/config/prod.exs

@@ -0,0 +1 @@
+import Config

openfeature/providers/elixir-provider/config/test.exs

@@ -0,0 +1,6 @@
+import Config
+
+# Prevents timeouts in ExUnit
+config :elixir_provider,
+  hackney_options: [timeout: 10_000, recv_timeout: 10_000],
+  tmp_dir_prefix: "wallaby_test"

openfeature/providers/elixir-provider/lib/elixir_provider.ex

@@ -0,0 +1,7 @@
+defmodule ElixirProvider do
+  @moduledoc """
+  `ElixirProvider` is a feature flag manager for controlling feature availability in Go applications.
+
+  It allows toggling features dynamically based on configurations from sources like databases and APIs, enabling flexible, real-time control over application behavior.
+  """
+end

openfeature/providers/elixir-provider/lib/provider/application.ex

@@ -0,0 +1,20 @@
+defmodule ElixirProvider.Application do
+  # See https://hexdocs.pm/elixir/Application.html
+  # for more information on OTP Applications
+  @moduledoc false
+
+  use Application
+
+  @impl true
+  def start(_type, _args) do
+    children = [
+      ExSd.ServerSupervisor
+    ]
+
+    # See https://hexdocs.pm/elixir/Supervisor.html
+    # for other strategies and supported options
+    opts = [strategy: :one_for_one, name: ExSd.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+
+end

openfeature/providers/elixir-provider/lib/provider/cache_controller.ex

@@ -0,0 +1,46 @@
+defmodule ElixirProvider.CacheController do
+  @moduledoc """
+  Controller for caching flag evaluations to avoid redundant API calls.
+  """
+
+  use GenServer
+  @flag_table :flag_cache
+
+  @spec start_link(any()) :: GenServer.on_start()
+  def start_link(_args) do
+    GenServer.start_link(__MODULE__, :ok, name: __MODULE__)
+  end
+
+  def get(flag_key, evaluation_hash) do
+    cache_key = build_cache_key(flag_key, evaluation_hash)
+
+    case :ets.lookup(@flag_table, cache_key) do
+      [{^cache_key, cached_value}] -> {:ok, cached_value}
+      [] -> :miss
+    end
+  end
+
+  def set(flag_key, evaluation_hash, value) do
+    cache_key = build_cache_key(flag_key, evaluation_hash)
+    :ets.insert(@flag_table, {cache_key, value})
+    :ok
+  end
+
+  def clear do
+    GenServer.stop(__MODULE__)
+    :ets.delete_all_objects(@flag_table)
+    :ets.insert(@flag_table, {:context, %{}})
+    :ok
+  end
+
+  defp build_cache_key(flag_key, evaluation_hash) do
+    "#{flag_key}-#{evaluation_hash}"
+  end
+
+  @impl true
+  def init(:ok) do
+    :ets.new(@flag_table, [:named_table, :set, :public])
+    :ets.insert(@flag_table, {:context, %{}})
+    {:ok, nil, :hibernate}
+  end
+end