nucleotide_count

elixir/nucleotide-count/test/nucleotide_count_test.exs

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+defmodule NucleotideCountTest do
+  use ExUnit.Case
+
+  describe "count" do
+    test "empty dna string has no adenine" do
+      assert NucleotideCount.count(~c"", ?A) == 0
+    end
+
+    test "one nucleotide" do
+      assert NucleotideCount.count(~c"G", ?G) == 1
+    end
+
+    test "repetitive cytosine gets counted" do
+      assert NucleotideCount.count(~c"CCCCC", ?C) == 5
+    end
+
+    test "counts only thymine" do
+      assert NucleotideCount.count(~c"GGGGGTAACCCGG", ?T) == 1
+    end
+  end
+
+  describe "histogram" do
+    test "empty dna string has no nucleotides" do
+      expected = %{?A => 0, ?T => 0, ?C => 0, ?G => 0}
+      assert NucleotideCount.histogram(~c"") == expected
+    end
+
+    test "one nucleotide" do
+      expected = %{?A => 0, ?T => 0, ?C => 0, ?G => 1}
+      assert NucleotideCount.histogram(~c"G") == expected
+    end
+
+    test "repetitive sequence has only guanine" do
+      expected = %{?A => 0, ?T => 0, ?C => 0, ?G => 8}
+      assert NucleotideCount.histogram(~c"GGGGGGGG") == expected
+    end
+
+    test "counts all nucleotides" do
+      s = ~c"AGCTTTTCATTCTGACTGCAACGGGCAATATGTCTCTGTGTGGATTAAAAAAAGAGTGTCTGATAGCAGC"
+      expected = %{?A => 20, ?T => 21, ?C => 12, ?G => 17}
+      assert NucleotideCount.histogram(s) == expected
+    end
+  end
+end

elixir/nucleotide-count/test/test_helper.exs

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+ExUnit.start()
+ExUnit.configure(exclude: :pending, trace: true)