Rewrite file-sniffer analysis (#412)

* Update submodule

* Add ideal file-sniffer analysis implementation

* Add tests for assert_call

* Show in test that special forms are local functions

* Add one more test case

lib/elixir_analyzer/constants.ex

@@ -90,7 +90,7 @@ defmodule ElixirAnalyzer.Constants do
     dna_encoding_use_tail_call_recursion: "elixir.dna-encoding.use_tail_call_recursion",
 
     # File Sniffer Comments
-    file_sniffer_use_pattern_matching: "elixir.file-sniffer.use_pattern_matching",
+    file_sniffer_use_bitstring: "elixir.file-sniffer.use_bitstring",
 
     # Freelancer Rates Comments
     freelancer_rates_apply_discount_function_reuse:

lib/elixir_analyzer/test_suite/file_sniffer.ex

@@ -6,155 +6,17 @@ defmodule ElixirAnalyzer.TestSuite.FileSniffer do
   alias ElixirAnalyzer.Constants
   use ElixirAnalyzer.ExerciseTest
 
-  feature "use pattern matching for bmp" do
+  assert_call "use <<>> to pattern match a bitstring in function body" do
     type :essential
-    find :any
-    comment Constants.file_sniffer_use_pattern_matching()
-
-    form do
-      <<0x42, 0x4D, _ignore>>
-    end
-
-    form do
-      <<0x42, 0x4D>>
-    end
-
-    form do
-      <<0x42::8, 0x4D::8, _ignore>>
-    end
-
-    form do
-      <<0x42::8, 0x4D::8>>
-    end
-
-    form do
-      <<0x42::size(8), 0x4D::size(8), _ignore>>
-    end
-
-    form do
-      <<0x42::size(8), 0x4D::size(8)>>
-    end
-  end
-
-  feature "use pattern matching for png" do
-    type :essential
-    find :any
-    comment Constants.file_sniffer_use_pattern_matching()
-
-    form do
-      <<0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A, _ignore>>
-    end
-
-    form do
-      <<0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A>>
-    end
-
-    form do
-      <<0x89::8, 0x50::8, 0x4E::8, 0x47::8, 0x0D::8, 0x0A::8, 0x1A::8, 0x0A::8, _ignore>>
-    end
-
-    form do
-      <<0x89::8, 0x50::8, 0x4E::8, 0x47::8, 0x0D::8, 0x0A::8, 0x1A::8, 0x0A::8>>
-    end
-
-    form do
-      <<0x89::size(8), 0x50::size(8), 0x4E::size(8), 0x47::size(8), 0x0D::size(8), 0x0A::size(8),
-        0x1A::size(8), 0x0A::size(8), _ignore>>
-    end
-
-    form do
-      <<0x89::size(8), 0x50::size(8), 0x4E::size(8), 0x47::size(8), 0x0D::size(8), 0x0A::size(8),
-        0x1A::size(8), 0x0A::size(8)>>
-    end
+    comment Constants.file_sniffer_use_bitstring()
+    called_fn name: :<<>>
+    calling_fn module: FileSniffer, name: :type_from_binary
   end
 
-  feature "use pattern matching for jpg" do
+  assert_call "use :: in bitstrings to specify segment type when pattern matching in function body" do
     type :essential
-    find :any
-    comment Constants.file_sniffer_use_pattern_matching()
-
-    form do
-      <<0xFF, 0xD8, 0xFF, _ignore>>
-    end
-
-    form do
-      <<0xFF, 0xD8, 0xFF>>
-    end
-
-    form do
-      <<0xFF::8, 0xD8::8, 0xFF::8, _ignore>>
-    end
-
-    form do
-      <<0xFF::8, 0xD8::8, 0xFF::8>>
-    end
-
-    form do
-      <<0xFF::size(8), 0xD8::size(8), 0xFF::size(8), _ignore>>
-    end
-
-    form do
-      <<0xFF::size(8), 0xD8::size(8), 0xFF::size(8)>>
-    end
-  end
-
-  feature "use pattern matching for gif" do
-    type :essential
-    find :any
-    comment Constants.file_sniffer_use_pattern_matching()
-
-    form do
-      <<0x47, 0x49, 0x46, _ignore>>
-    end
-
-    form do
-      <<0x47, 0x49, 0x46>>
-    end
-
-    form do
-      <<0x47::8, 0x49::8, 0x46::8, _ignore>>
-    end
-
-    form do
-      <<0x47::8, 0x49::8, 0x46::8>>
-    end
-
-    form do
-      <<0x47::size(8), 0x49::size(8), 0x46::size(8), _ignore>>
-    end
-
-    form do
-      <<0x47::size(8), 0x49::size(8), 0x46::size(8)>>
-    end
-  end
-
-  feature "use pattern matching for exe" do
-    type :essential
-    find :any
-    comment Constants.file_sniffer_use_pattern_matching()
-
-    form do
-      <<0x7F, 0x45, 0x4C, 0x46, _ignore>>
-    end
-
-    form do
-      <<0x7F, 0x45, 0x4C, 0x46>>
-    end
-
-    form do
-      <<0x7F::8, 0x45::8, 0x4C::8, 0x46::8, _ignore>>
-    end
-
-    form do
-      <<0x7F::8, 0x45::8, 0x4C::8, 0x46::8>>
-    end
-
-    form do
-      <<0x7F::size(8), 0x45::size(8), 0x4C::size(8), 0x46::size(8), _ignore>>
-    end
-
-    form do
-      <<0x7F::size(8), 0x45::size(8), 0x4C::size(8), 0x46::size(8)>>
-    end
+    comment Constants.file_sniffer_use_bitstring()
+    called_fn name: :"::"
+    calling_fn module: FileSniffer, name: :type_from_binary
   end
 end

test/elixir_analyzer/exercise_test/assert_call/function_head_call_test.exs

@@ -0,0 +1,114 @@
+defmodule ElixirAnalyzer.ExerciseTest.AssertCall.FunctionHeadCallTest do
+  use ElixirAnalyzer.ExerciseTestCase,
+    exercise_test_module: ElixirAnalyzer.Support.AnalyzerVerification.AssertCall.FunctionHeadCall
+
+  test_exercise_analysis "calls in function head count", comments: [] do
+    [
+      defmodule AssertCallVerification do
+        def main_function(@jackpot) do
+          :win
+        end
+
+        def main_function(x) when x > 100 do
+          :too_much
+        end
+
+        def main_function([x | rest]) when is_integer(x) do
+          main_function(x)
+        end
+      end,
+      defmodule AssertCallVerification do
+        def main_function(@jackpot) do
+          :win
+        end
+
+        def main_function([x | rest]) when is_integer(x) and x > 100 do
+          :too_much
+        end
+      end,
+      defmodule AssertCallVerification do
+        def main_function(x) when x == @jackpot do
+          :win
+        end
+
+        def main_function(a, b, [x | rest]) when is_integer(x) and x > 100 do
+          :too_much
+        end
+      end,
+      defmodule AssertCallVerification do
+        def main_function(x) when x == @jackpot do
+          :win
+        end
+
+        def main_function(%{list: [x | rest]}) when is_integer(x) and x > 100 do
+          :too_much
+        end
+      end
+    ]
+  end
+
+  test_exercise_analysis "indirect calls in function head count", comments: [] do
+    [
+      defmodule AssertCallVerification do
+        def main_function(x) do
+          helper_function(x)
+        end
+
+        def helper_function(@jackpot) do
+          :win
+        end
+
+        def helper_function([x | rest]) when is_integer(x) do
+          main_function(x)
+        end
+
+        defp helper_function(x) when x > 100 do
+          :too_much
+        end
+      end
+    ]
+  end
+
+  test_exercise_analysis "calls from the wrong function",
+    comments: [
+      "didn't find any call to Kernel.is_integer/1 from main_function/1",
+      "didn't find any call to |/2 from main_function/1",
+      "didn't find any call to Kernel.@/1 from main_function/1"
+    ] do
+    [
+      defmodule AssertCallVerification do
+        def main_function() do
+          nil
+        end
+
+        def wrong_function(@jackpot) do
+          :win
+        end
+
+        def wrong_function(x) when x > 100 do
+          :too_much
+        end
+
+        def wrong_function([x | rest]) when is_integer(x) do
+          wrong_function(x)
+        end
+      end
+    ]
+  end
+
+  test_exercise_analysis "no calls",
+    comments: [
+      "didn't find any call to Kernel.>/2 from anywhere",
+      "didn't find any call to Kernel.is_integer/1 from main_function/1",
+      "didn't find any call to |/2 from main_function/1",
+      "didn't find any call to Kernel.@/1 from main_function/1"
+    ] do
+    [
+      defmodule AssertCallVerification do
+        def main_function(x) when x >= 100 do
+          :too_much
+        end
+      end
+    ]
+  end
+end

test/elixir_analyzer/exercise_test/assert_call/kernel_functions_test.exs

@@ -7,7 +7,8 @@ defmodule ElixirAnalyzer.ExerciseTest.AssertCall.KernelTest do
       "didn't find a call to Kernel.dbg/0",
       "didn't find a call to dbg/0",
       "didn't find a call to Kernel.self/0",
-      "didn't find a call to self/0"
+      "didn't find a call to self/0",
+      "didn't find a call to <<>>/1"
     ] do
     defmodule AssertCallVerification do
       def function() do
@@ -62,4 +63,29 @@ defmodule ElixirAnalyzer.ExerciseTest.AssertCall.KernelTest do
       end
     ]
   end
+
+  test_exercise_analysis "Calling <<>>/1",
+    comments_exclude: [
+      "didn't find a call to <<>>/1"
+    ] do
+    [
+      defmodule AssertCallVerification do
+        def function() do
+          <<a, b, c>> = <<1, 2, 3>>
+          a
+        end
+      end,
+      defmodule AssertCallVerification do
+        def function() do
+          <<a, b, c>> = <<1, 2, 3>>
+
+          if b > 2 do
+            a + c
+          else
+            nil
+          end
+        end
+      end
+    ]
+  end
 end