util: implement string padding function

Co-authored-by: Konstantin Akimov <knstqq@gmail.com>

Author: kwvg

src/test/util_tests.cpp

@@ -1828,4 +1828,26 @@ BOOST_AUTO_TEST_CASE(clearshrink_test)
     }
 }
 
+BOOST_AUTO_TEST_CASE(padding_test)
+{
+    /* By default strings will be padded to the left */
+    BOOST_CHECK_EQUAL(PadString("example", 8), " example");
+
+    /* Check padding works on the correct side */
+    BOOST_CHECK_EQUAL(PadString("example", 8, /*left=*/true),  " example");
+    BOOST_CHECK_EQUAL(PadString("example", 8, /*left=*/false), "example ");
+
+    /* Padding lesser than the string size should return the string */
+    BOOST_CHECK_EQUAL(PadString("example", 6), "example");
+
+    /* Padding equal to the string size should return the string */
+    BOOST_CHECK_EQUAL(PadString("example", 7), "example");
+
+    /* Padding an empty string with zero length should return an empty string */
+    BOOST_CHECK(PadString("", 0).empty());
+
+    /* An empty string should be padded if non-zero length specified */
+    BOOST_CHECK_EQUAL(PadString("", 1), " ");
+}
+
 BOOST_AUTO_TEST_SUITE_END()

src/util/string.h

@@ -57,6 +57,12 @@ void ReplaceAll(std::string& in_out, const std::string& search, const std::strin
     return std::string(RemovePrefixView(str, prefix));
 }
 
+[[nodiscard]] inline std::string PadString(std::string str, std::string::size_type size, bool left = true)
+{
+    if (size <= str.size()) return str;
+    return left ? std::string(size - str.size(), ' ').append(str) : str.append(std::string(size - str.size(), ' '));
+}
+
 /**
  * Join all container items. Typically used to concatenate strings but accepts
  * containers with elements of any type.