Improved sequence diagram message comment formatting

src/sequence_diagram/generators/plantuml/sequence_diagram_generator.cc

@@ -287,19 +287,10 @@ void generator::generate_message_comment(
     if (!from)
         return;
 
-    if (m.type() == message_t::kCall) {
-        const auto &to = model().get_participant<model::participant>(m.to());
-        if (!to)
-            return;
+    ostr << "note over " << generate_alias(from.value()) << '\n';
 
-        ostr << "note over " << generate_alias(from.value()) << ", "
-             << generate_alias(to.value()) << '\n';
-    }
-    else {
-        ostr << "note over " << generate_alias(from.value()) << '\n';
-    }
+    ostr << util::format_message_comment(m.comment().value()) << '\n';
 
-    ostr << m.comment().value() << '\n';
     ostr << "end note" << '\n';
 }
 

src/util/util.cc

@@ -199,6 +199,28 @@ std::vector<std::string> split(
     return result;
 }
 
+std::vector<std::string> split_isspace(std::string str)
+{
+    std::vector<std::string> result;
+
+    while (static_cast<unsigned int>(!str.empty()) != 0U) {
+        auto index = std::find_if(
+            str.begin(), str.end(), [](auto c) { return std::isspace(c); });
+        if (index != str.end()) {
+            auto tok = str.substr(0, std::distance(str.begin(), index));
+            if (!tok.empty())
+                result.push_back(std::move(tok));
+            str = str.substr(std::distance(str.begin(), index) + 1);
+        }
+        else {
+            if (!str.empty())
+                result.push_back(str);
+            str = "";
+        }
+    }
+    return result;
+}
+
 std::string join(
     const std::vector<std::string> &toks, std::string_view delimiter)
 {
@@ -344,4 +366,40 @@ std::filesystem::path ensure_path_is_absolute(
     return result;
 }
 
+std::string format_message_comment(const std::string &comment, unsigned width)
+{
+    if (width == 0)
+        return comment;
+
+    std::string result;
+
+    if (comment.empty())
+        return result;
+
+    auto tokens = split_isspace(comment);
+
+    if (tokens.empty())
+        return result;
+
+    unsigned current_line_length{0};
+    for (auto it = tokens.begin(); it != tokens.end(); it++) {
+        if (current_line_length < width) {
+            result += *it;
+            result += ' ';
+        }
+        else {
+            result.back() = '\n';
+            current_line_length = 0;
+            result += *it;
+            result += ' ';
+        }
+
+        current_line_length += it->size() + 1;
+    }
+
+    result.pop_back();
+
+    return result;
+}
+
 } // namespace clanguml::util

src/util/util.h

@@ -167,6 +167,8 @@ std::string get_os_name();
 std::vector<std::string> split(
     std::string str, std::string_view delimiter, bool skip_empty = true);
 
+std::vector<std::string> split_isspace(std::string str);
+
 /**
  * @brief Remove and erase elements from a vector
  *
@@ -424,4 +426,6 @@ std::string path_to_url(const std::filesystem::path &p);
 std::filesystem::path ensure_path_is_absolute(const std::filesystem::path &p,
     const std::filesystem::path &root = std::filesystem::current_path());
 
+std::string format_message_comment(const std::string &c, unsigned width = 25);
+
 } // namespace clanguml::util

tests/t20029/t20029.cc

@@ -12,7 +12,10 @@ template <typename T> class Encoder : public T {
 public:
     bool send(std::string &&msg)
     {
-        return T::send(std::move(encode(std::move(msg))));
+        return T::send(std::move(
+            // Encode the message using Base64 encoding and pass it to the next
+            // layer
+            encode(std::move(msg))));
     }
 
 protected:
@@ -27,6 +30,7 @@ public:
 
         int retryCount = 5;
 
+        // Repeat until send() succeeds or retry count is exceeded
         while (retryCount--) {
             if (T::send(buffer))
                 return true;

tests/test_util.cc

@@ -396,3 +396,24 @@ TEST_CASE("Test tokenize_unexposed_template_parameter", "[unit-test]")
         CHECK(r[i++] == ")");
     }
 }
+
+TEST_CASE("Test format_message_comment", "[unit-test]")
+{
+    using namespace clanguml::util;
+
+    CHECK(format_message_comment("\n\n   ABCD \n", 0) == "\n\n   ABCD \n");
+    CHECK(format_message_comment("\n\n   ABCD \n") == "ABCD");
+
+    CHECK(format_message_comment(
+              "Repeat until send() succeeds or retry count is exceeded") ==
+        "Repeat until send() succeeds\nor retry count is exceeded");
+
+    CHECK(format_message_comment("12345678", 5) == "12345678");
+
+    CHECK(format_message_comment("") == "");
+
+    CHECK(format_message_comment(" ") == "");
+
+    CHECK(format_message_comment("This is a url: http://example.com/test/12345",
+              15) == "This is a url:\nhttp://example.com/test/12345");
+}