Added Elixir binaries, strings and charlists tests

test/elixir_binaries_strings_and_charlists_test.exs

@@ -0,0 +1,112 @@
+defmodule BinariesStringsCharlistsTest do
+  use ExUnit.Case
+
+  describe "Binaries, strings, and charlists" do
+
+    test "check if a string is a binary" do
+      string = "hello"
+      assert is_binary(string)
+    end
+
+    test "unicode and code points" do
+      assert ?a == 97
+      assert ?ł == 322
+      assert "\u0061" == "a"
+    end
+
+    test "utf-8 encoding and byte size" do
+      string = "héllo"
+      assert String.length(string) == 5
+      assert byte_size(string) == 6
+    end
+
+    test "string graphemes and code points" do
+      assert String.codepoints("👩‍🚒") == ["👩", "‍", "🚒"]
+      assert String.graphemes("👩‍🚒") == ["👩‍🚒"]
+      assert String.length("👩‍🚒") == 1
+    end
+
+    test "viewing string's binary representation" do
+      assert "hełło" <> <<0>> == <<104, 101, 197, 130, 197, 130, 111, 0>>
+      assert IO.inspect("hełło", binaries: :as_binaries) == <<104, 101, 197, 130, 197, 130, 111>>
+    end
+
+    test "bitstrings" do
+      assert <<42>> == <<42::8>>
+      assert <<3::4>> == <<3::size(4)>>
+      assert <<0::1, 0::1, 1::1, 1::1>> == <<3::4>>
+      assert <<1>> == <<257>>
+    end
+
+    test "binaries" do
+      assert is_bitstring(<<3::4>>)
+      assert not is_binary(<<3::4>>)
+      assert is_binary(<<0, 255, 42>>)
+      assert is_binary(<<42::16>>)
+    end
+
+    test "pattern matching on binaries" do
+      assert <<0, 1, x>> = <<0, 1, 2>>
+      assert x == 2
+      assert_raise MatchError, fn ->
+        <<0, 1, _x>> = <<0, 1, 2, 3>>
+      end
+
+      assert <<0, 1, x::binary>> = <<0, 1, 2, 3>>
+      assert x == <<2, 3>>
+
+      assert <<head::binary-size(2), rest::binary>> = <<0, 1, 2, 3>>
+      assert head == <<0, 1>>
+      assert rest == <<2, 3>>
+    end
+
+    test "validating binaries and strings" do
+      assert is_binary("hello")
+      assert is_binary(<<239, 191, 19>>)
+      assert not String.valid?(<<239, 191, 19>>)
+    end
+
+    test "concatenating binaries and strings" do
+      assert "a" <> "ha" == "aha"
+      assert <<0, 1>> <> <<2, 3>> == <<0, 1, 2, 3>>
+    end
+
+    test "pattern matching on strings" do
+      assert <<head, rest::binary>> = "banana"
+      assert head == ?b
+      assert rest == "anana"
+
+      assert "ü" <> <<0>> == <<195, 188, 0>>
+      assert <<x, rest::binary>> = "über"
+      assert x != ?ü
+      assert rest == <<188, 98, 101, 114>>
+
+      assert <<x::utf8, rest::binary>> = "über"
+      assert x == ?ü
+      assert rest == "ber"
+    end
+
+    test "charlists" do
+      assert ~c"hello" == [?h, ?e, ?l, ?l, ?o]
+      assert ~c"hełło" == [104, 101, 322, 322, 111]
+      assert is_list(~c"hełło")
+
+      heartbeats_per_minute = [99, 97, 116]
+      assert inspect(heartbeats_per_minute, charlists: :as_list) == "[99, 97, 116]"
+
+      assert to_charlist("hełło") == [104, 101, 322, 322, 111]
+      assert to_string(~c"hełło") == "hełło"
+      assert to_string(:hello) == "hello"
+      assert to_string(1) == "1"
+    end
+
+    test "concatenating charlists" do
+      assert ~c"this " ++ ~c"works" == ~c"this works"
+      # assert_raise ArgumentError, fn ->
+      #   "he" ++ "llo"
+      # end
+      assert "he" <> "llo" == "hello"
+    end
+
+  end
+end