encoding/base64: add decode_into, add tests

tests/core/encoding/base64/base64.odin

@@ -0,0 +1,60 @@
+package test_encoding_base64
+
+import "core:encoding/base64"
+import "core:fmt"
+import "core:intrinsics"
+import "core:os"
+import "core:reflect"
+import "core:testing"
+
+TEST_count := 0
+TEST_fail  := 0
+
+when ODIN_TEST {
+	expect_value :: testing.expect_value
+
+} else {
+	expect_value :: proc(t: ^testing.T, value, expected: $T, loc := #caller_location) -> bool where intrinsics.type_is_comparable(T) {
+		TEST_count += 1
+		ok := value == expected || reflect.is_nil(value) && reflect.is_nil(expected)
+		if !ok {
+			TEST_fail += 1
+			fmt.printf("[%v] expected %v, got %v\n", loc, expected, value)
+		}
+		return ok
+	}
+}
+
+main :: proc() {
+	t := testing.T{}
+
+	test_encoding(&t)
+	test_decoding(&t)
+
+	fmt.printf("%v/%v tests successful.\n", TEST_count - TEST_fail, TEST_count)
+	if TEST_fail > 0 {
+		os.exit(1)
+	}
+}
+
+@(test)
+test_encoding :: proc(t: ^testing.T) {
+	expect_value(t, base64.encode(transmute([]byte)string("")), "")
+	expect_value(t, base64.encode(transmute([]byte)string("f")), "Zg==")
+	expect_value(t, base64.encode(transmute([]byte)string("fo")), "Zm8=")
+	expect_value(t, base64.encode(transmute([]byte)string("foo")), "Zm9v")
+	expect_value(t, base64.encode(transmute([]byte)string("foob")), "Zm9vYg==")
+	expect_value(t, base64.encode(transmute([]byte)string("fooba")), "Zm9vYmE=")
+	expect_value(t, base64.encode(transmute([]byte)string("foobar")), "Zm9vYmFy")
+}
+
+@(test)
+test_decoding :: proc(t: ^testing.T) {
+	expect_value(t, string(base64.decode("")), "")
+	expect_value(t, string(base64.decode("Zg==")), "f")
+	expect_value(t, string(base64.decode("Zm8=")), "fo")
+	expect_value(t, string(base64.decode("Zm9v")), "foo")
+	expect_value(t, string(base64.decode("Zm9vYg==")), "foob")
+	expect_value(t, string(base64.decode("Zm9vYmE=")), "fooba")
+	expect_value(t, string(base64.decode("Zm9vYmFy")), "foobar")
+}