fixing bugs exposed by dialyzer

Author: boydm

lib/scenic/cache/file.ex

@@ -81,10 +81,7 @@ defmodule Scenic.Cache.File do
   defp do_unzip(data, opts) do
     case opts[:decompress] do
       true ->
-        case :zlib.gunzip(data) do
-          bin when is_binary(bin) -> {:ok, bin}
-          _ -> {:error, :gunzip}
-        end
+        {:ok, :zlib.gunzip(data)}
 
       _ ->
         # not decompressing

lib/scenic/cache/hash.ex

@@ -34,18 +34,16 @@ defmodule Scenic.Cache.Hash do
 
   # --------------------------------------------------------
   def binary(data, hash_type) do
-    valid_hash_type!(hash_type)
-    |> :crypto.hash(data)
-    |> Base.url_encode64(padding: false)
+    case valid_hash_type?(hash_type) do
+      true -> {:ok, :crypto.hash(hash_type, data) |> Base.url_encode64(padding: false)}
+      false -> {:error, :invalid_hash_type}
+    end
   end
 
   def binary!(data, hash_type) do
-    {:ok, hash} =
-      valid_hash_type!(hash_type)
-      |> :crypto.hash(data)
-      |> Base.url_encode64(padding: false)
-
-    hash
+    valid_hash_type!(hash_type)
+    |> :crypto.hash(data)
+    |> Base.url_encode64(padding: false)
   end
 
   # --------------------------------------------------------
@@ -99,15 +97,15 @@ defmodule Scenic.Cache.Hash do
 
   # --------------------------------------------------------
   def verify(data, hash, hash_type) do
-    case binary(data, hash_type) == hash do
-      true -> {:ok, data}
-      false -> {:error, :hash_failure}
+    case binary(data, hash_type) do
+      {:ok, ^hash} -> {:ok, data}
+      _ -> {:error, :hash_failure}
     end
   end
 
   # --------------------------------------------------------
   def verify!(data, hash, hash_type) do
-    case binary(data, hash_type) == hash do
+    case binary!(data, hash_type) == hash do
       true -> data
       false -> raise Error
     end

lib/scenic/cache/term.ex

@@ -19,9 +19,8 @@ defmodule Scenic.Cache.Term do
   # hashes. Is also slower because it has to load the file and compute the hash
   # to use as a key even it is is already loaded into the cache.
   def load(path, :insecure, opts) do
-    with {:ok, data} <- Cache.File.read(path, :insecure, opts) do
-      hash = Hash.binary(data, opts[:hash] || :sha)
-
+    with {:ok, data} <- Cache.File.read(path, :insecure, opts),
+    {:ok, hash} <- Hash.binary(data, opts[:hash] || :sha) do
       case Cache.claim(hash, opts[:scope]) do
         true ->
           {:ok, hash}

lib/utilities.ex

@@ -20,7 +20,7 @@ defmodule Scenic.Mixfile do
       make_targets: ["all"],
       make_clean: ["clean"],
       make_env: make_env(),
-      dialyzer: [plt_add_deps: :transitive, plt_add_apps: [:mix, :iex, :scenic_math]],
+      dialyzer: [plt_add_deps: :transitive, plt_add_apps: [:mix, :iex]],
       test_coverage: [tool: ExCoveralls],
       preferred_cli_env: [
         coveralls: :test,

mix.exs

@@ -29,13 +29,25 @@ defmodule Scenic.Cache.HashTest do
   test "binary computes a hash for some binary data" do
     data = "some data. af98hwu4lhrliw4uhtliuhet;giojres;ihg;usdhg"
     expected_hash = :crypto.hash(:sha, data) |> Base.url_encode64(padding: false)
-    assert Hash.binary(data, :sha) == expected_hash
+    assert Hash.binary(data, :sha) == {:ok, expected_hash}
+  end
+
+  test "binary rejects invalid hash types" do
+    data = "some data. af98hwu4lhrliw4uhtliuhet;giojres;ihg;usdhg"
+    assert Hash.binary(data, :invalid) == {:error, :invalid_hash_type}
   end
 
   test "binary! computes a hash for some binary data" do
     data = "some data. af98hwu4lhrliw4uhtliuhet;giojres;ihg;usdhg"
     expected_hash = :crypto.hash(:sha, data) |> Base.url_encode64(padding: false)
-    assert Hash.binary(data, :sha) == expected_hash
+    assert Hash.binary!(data, :sha) == expected_hash
+  end
+
+  test "binary! raises on an invalid hash type" do
+    data = "some data. af98hwu4lhrliw4uhtliuhet;giojres;ihg;usdhg"
+    assert_raise Scenic.Cache.Hash.Error, fn ->
+      Hash.binary!(data, :invalid)
+    end
   end
 
   # ============================================================================
@@ -73,7 +85,7 @@ defmodule Scenic.Cache.HashTest do
 
   test "verify returns {:ok, data} when the hash checks out ok" do
     data = "This is some data to hash - awleiufhoq34htuwehtljwuh5toihu"
-    expected = Hash.binary(data, :sha)
+    expected = Hash.binary!(data, :sha)
     assert Hash.verify(data, expected, :sha) == {:ok, data}
   end
 
@@ -87,7 +99,7 @@ defmodule Scenic.Cache.HashTest do
 
   test "verify! returns data when the hash checks out ok" do
     data = "This is some data to hash - awleiufhoq34htuwehtljwuh5toihu"
-    expected = Hash.binary(data, :sha)
+    expected = Hash.binary!(data, :sha)
     assert Hash.verify!(data, expected, :sha) == data
   end