From 8da5ce49ef1857c8d3231e929c17bfa0fcacf7bf Mon Sep 17 00:00:00 2001
From: SEK1RO <vlad@sek1.ro>
Date: Thu, 26 Sep 2024 20:05:38 +0300
Subject: [PATCH] fix(base64): coverage

---
 Makefile             |  1 +
 src/base64.cpp       | 33 +++++++++++++++------------------
 test/test-base64.cpp | 12 ++++++++++++
 3 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/Makefile b/Makefile
index 525492d..77bf9be 100644
--- a/Makefile
+++ b/Makefile
@@ -83,6 +83,7 @@ docs:
 	doxygen Doxyfile
 
 cover: ${DIRS} ${patsubst %, ${BINDIR}/%${-g}-cov, ${TESTS}}
+	rm -f **/*.gcda
 	${patsubst %, ./${BINDIR}/%${-g}-cov;, ${TESTS}}
 	gcovr --html-nested cov/index.html --txt --exclude-throw-branches
 
diff --git a/src/base64.cpp b/src/base64.cpp
index 8976085..e00972b 100644
--- a/src/base64.cpp
+++ b/src/base64.cpp
@@ -74,25 +74,22 @@ namespace base64
             str[i * 4 + 3] = digits[data[i * 3 + 2] & 0x3F];
         }
         uint64_t last_idx = data_size / 3 * 4;
-        if (last_idx + 3 < str_size)
+        switch (data_size % 3)
         {
-            switch (data_size % 3)
-            {
-            case 1:
-                str[last_idx] = digits[data[data_size - 1] >> 2];
-                str[last_idx + 1] = digits[data[data_size - 1] << 4 & 0x30];
-                str[last_idx + 2] = '=';
-                str[last_idx + 3] = '=';
-                break;
-            case 2:
-                str[last_idx] = digits[data[data_size - 2] >> 2];
-                str[last_idx + 1] = digits[(data[data_size - 2] << 4 | data[data_size - 1] >> 4) & 0x3F];
-                str[last_idx + 2] = digits[data[data_size - 1] & 0x0F];
-                str[last_idx + 3] = '=';
-                break;
-            default:
-                break;
-            }
+        case 1:
+            str[last_idx] = digits[data[data_size - 1] >> 2];
+            str[last_idx + 1] = digits[data[data_size - 1] << 4 & 0x30];
+            str[last_idx + 2] = '=';
+            str[last_idx + 3] = '=';
+            break;
+        case 2:
+            str[last_idx] = digits[data[data_size - 2] >> 2];
+            str[last_idx + 1] = digits[(data[data_size - 2] << 4 | data[data_size - 1] >> 4) & 0x3F];
+            str[last_idx + 2] = digits[data[data_size - 1] & 0x0F];
+            str[last_idx + 3] = '=';
+            break;
+        default:
+            break;
         }
     }
     std::string encode(std::span<const uint8_t> data) noexcept
diff --git a/test/test-base64.cpp b/test/test-base64.cpp
index f0877da..92d2316 100644
--- a/test/test-base64.cpp
+++ b/test/test-base64.cpp
@@ -28,6 +28,12 @@ TEST(base64, encode)
 {
     for (auto it : tests)
         EXPECT_EQ(it.first, encode(hex::decode(it.second)));
+
+    std::vector<uint8_t> data = {0x74, 0x65, 0x73, 0x74};
+    std::string str = "";
+    EXPECT_THROW(encode(data.data(), std::numeric_limits<uint64_t>::max(), str.data(), str.size()), std::overflow_error);
+    EXPECT_THROW(encode(data.data(), data.size(), str.data(), str.size()), std::length_error);
+    EXPECT_NO_THROW(encode(data.data(), 0, str.data(), str.size()));
 }
 TEST(base64, encode_1e7)
 {
@@ -38,6 +44,12 @@ TEST(base64, decode)
 {
     for (auto it : tests)
         EXPECT_EQ(hex::encode(decode(it.first)), it.second);
+
+    std::vector<uint8_t> data = {0x61, 0x6e, 0x6f};
+    EXPECT_THROW(decode("FFF", 3, data.data(), data.size()), std::logic_error);
+    EXPECT_THROW(decode("!@#!", 4, data.data(), data.size()), std::logic_error);
+    EXPECT_THROW(decode("FF==", 2, data.data(), 0), std::length_error);
+    EXPECT_NO_THROW(decode(""       , 0, data.data(), 0));
 }
 TEST(base64, decode_1e7)
 {