finish smart_split

src/group_handler/handle_mention.rs

@@ -806,46 +806,69 @@ fn smart_split(msg : &str, prefix: Option<String>, limit: usize) -> Vec<String>
     let mut parts_to_send = vec![];
     let mut this_piece = prefix.clone();
     for l in msg.split("\n") {
+        println!("* Line: {:?}", l);
         if this_piece.len() + l.len() == limit {
+            println!("exactly fits within limit");
+            // this line exactly reaches the limit
             this_piece.push_str(l);
             parts_to_send.push(std::mem::take(&mut this_piece).trim().to_owned());
             this_piece.push_str(&prefix);
         } else if this_piece.len() + l.len() > limit {
+            println!("too long to append (already {} + new {})", this_piece.len(), l.len());
+            // line too long to append
+            if this_piece != prefix {
                 let trimmed = this_piece.trim();
                 if !trimmed.is_empty() {
+                    println!("flush buffer: {:?}", trimmed);
                     parts_to_send.push(trimmed.to_owned());
                 }
+            }
 
-            // start new piece
+            // start new piece with the line. If the line is too long, break it up.
             this_piece = format!("{}{}", prefix, l);
 
             while this_piece.len() > limit {
-                let to_send = if let Some(last_space) = (&this_piece[..limit]).rfind(' ') {
-                    let mut p = this_piece.split_off(last_space);
+                // line too long, try splitting at the last space, if any
+                let to_send = if let Some(last_space) = (&this_piece[..=limit]).rfind(' ') {
+                    println!("line split at word boundary");
+                    let mut p = this_piece.split_off(last_space + 1);
                     std::mem::swap(&mut p, &mut this_piece);
                     p
                 } else {
+                    println!("line split at exact len (no word boundary found)");
                     let mut p = this_piece.split_off(limit);
                     std::mem::swap(&mut p, &mut this_piece);
                     p
                 };
-                parts_to_send.push(to_send);
-                this_piece = format!("{}{}", prefix, this_piece);
+                let part_trimmed = to_send.trim();
+                println!("flush buffer: {:?}", part_trimmed);
+                parts_to_send.push(part_trimmed.to_owned());
+                this_piece = format!("{}{}", prefix, this_piece.trim());
             }
             this_piece.push('\n');
         } else {
+            println!("append line");
+            // this line still fits comfortably
             this_piece.push_str(l);
             this_piece.push('\n');
         }
     }
 
+    if this_piece != prefix {
+        let leftover_trimmed = this_piece.trim();
+        if !leftover_trimmed.is_empty() {
+            println!("flush buffer: {:?}", leftover_trimmed);
+            parts_to_send.push(leftover_trimmed.to_owned());
+        }
+    }
+
     parts_to_send
 }
 
 #[cfg(test)]
 mod test {
     #[test]
-    fn test_smart_split1() {
+    fn test_smart_split_lines() {
         let to_split = "a234567890\nb234567890\nc234567890\nd234\n67890\ne234567890\n";
 
         let parts = super::smart_split(to_split, None, 10);
@@ -859,7 +882,7 @@ mod test {
     }
 
     #[test]
-    fn test_smart_split2() {
+    fn test_smart_split_nosplit() {
         let to_split = "foo\nbar\nbaz";
 
         let parts = super::smart_split(to_split, None, 1000);
@@ -869,7 +892,7 @@ mod test {
     }
 
     #[test]
-    fn test_smart_split3() {
+    fn test_smart_split_nosplit_prefix() {
         let to_split = "foo\nbar\nbaz";
         let parts = super::smart_split(to_split, Some("PREFIX".to_string()), 1000);
         assert_eq!(vec![
@@ -878,7 +901,7 @@ mod test {
     }
 
     #[test]
-    fn test_smart_split4() {
+    fn test_smart_split_prefix_each() {
         let to_split = "1234\n56\n7";
         let parts = super::smart_split(to_split, Some("PREFIX".to_string()), 10);
         assert_eq!(vec![
@@ -886,4 +909,79 @@ mod test {
             "PREFIX56\n7".to_string(),
         ], parts);
     }
+
+    #[test]
+    fn test_smart_split_words() {
+        let to_split = "one two three four five six seven eight nine ten";
+        let parts = super::smart_split(to_split, None, 10);
+        assert_eq!(vec![
+            "one two".to_string(),
+            "three four".to_string(),
+            "five six".to_string(),
+            "seven".to_string(),
+            "eight nine".to_string(),
+            "ten".to_string(),
+        ], parts);
+    }
+
+    #[test]
+    fn test_smart_split_words_multispace() {
+        let to_split = "one two      three four    five six     seven    eight nine     ten   ";
+        let parts = super::smart_split(to_split, None, 10);
+        assert_eq!(vec![
+            "one two".to_string(),
+            "three four".to_string(),
+            "five six".to_string(),
+            "seven".to_string(),
+            "eight nine".to_string(),
+            "ten".to_string(),
+        ], parts);
+    }
+
+    #[test]
+    fn test_smart_split_words_longword() {
+        let to_split = "one two threefourfive six";
+        let parts = super::smart_split(to_split, None, 10);
+        assert_eq!(vec![
+            "one two".to_string(),
+            "threefourf".to_string(),
+            "ive six".to_string(),
+        ], parts);
+    }
+
+    #[test]
+    fn test_smart_split_words_prefix() {
+        let to_split = "one two three four five six seven eight nine ten";
+        let parts = super::smart_split(to_split, Some("PREFIX".to_string()), 15);
+        assert_eq!(vec![
+            "PREFIXone two".to_string(),
+            "PREFIXthree".to_string(),
+            "PREFIXfour five".to_string(),
+            "PREFIXsix seven".to_string(),
+            "PREFIXeight".to_string(),
+            "PREFIXnine ten".to_string(),
+        ], parts);
+    }
+
+    #[test]
+    fn test_smart_split_realistic() {
+        let to_split = "\
+            Lorem ipsum dolor sit amet, consectetur adipiscing elit.\n\
+            Aenean venenatis libero ac ex suscipit, nec efficitur arcu convallis.\n\
+            Nulla ante neque, efficitur nec fermentum a, fermentum nec nisl.\n\
+            Sed dolor ex, vestibulum at malesuada ut, faucibus ac ante.\n\
+            Nullam scelerisque magna dui, id tempor purus faucibus sit amet.\n\
+            Curabitur pretium condimentum pharetra.\n\
+            Aenean dictum, tortor et ultrices fermentum, mauris erat vehicula lectus.\n\
+            Nec varius mauris sem sollicitudin dolor. Nunc porta in urna nec vulputate.";
+        let parts = super::smart_split(to_split, Some("@pepa@pig.club ".to_string()), 140);
+        assert_eq!(vec![
+            "@pepa@pig.club Lorem ipsum dolor sit amet, consectetur adipiscing elit.".to_string(),
+            "@pepa@pig.club Aenean venenatis libero ac ex suscipit, nec efficitur arcu convallis.".to_string(),
+            "@pepa@pig.club Nulla ante neque, efficitur nec fermentum a, fermentum nec nisl.\nSed dolor ex, vestibulum at malesuada ut, faucibus ac ante.".to_string(),
+            "@pepa@pig.club Nullam scelerisque magna dui, id tempor purus faucibus sit amet.\nCurabitur pretium condimentum pharetra.".to_string(),
+            "@pepa@pig.club Aenean dictum, tortor et ultrices fermentum, mauris erat vehicula lectus.".to_string(),
+            "@pepa@pig.club Nec varius mauris sem sollicitudin dolor. Nunc porta in urna nec vulputate.".to_string(),
+        ], parts);
+    }
 }