Add a test for word wrapping fallback.

tests/wrap_word_fallback.rs

@@ -0,0 +1,34 @@
+use cosmic_text::{Attrs, Buffer, FontSystem, Metrics, Shaping, Wrap};
+
+// Tests the ability to fallback to glyph wrapping when a word can't fit on a line by itself.
+// No line should ever overflow the buffer size.
+#[test]
+fn wrap_word_fallback() {
+    let mut font_system = FontSystem::new();
+    let metrics = Metrics::new(14.0, 20.0);
+
+    let mut buffer = Buffer::new(&mut font_system, metrics);
+
+    let mut buffer = buffer.borrow_with(&mut font_system);
+
+    buffer.set_wrap(Wrap::Word);
+    buffer.set_text("Lorem ipsum dolor sit amet, qui minim labore adipisicing minim sint cillum sint consectetur cupidatat.", Attrs::new().family(cosmic_text::Family::Name("Inter")), Shaping::Advanced);
+    buffer.set_size(50.0, 1000.0);
+
+    buffer.shape_until_scroll(false);
+
+    let measured_size = measure(&buffer);
+
+    assert!(
+        measured_size <= buffer.size().0,
+        "Measured width is larger than buffer width\n{} <= {}",
+        measured_size,
+        buffer.size().0
+    );
+}
+
+fn measure(buffer: &Buffer) -> f32 {
+    buffer
+        .layout_runs()
+        .fold(0.0f32, |width, run| width.max(run.line_w))
+}