Merge pull request #1836 from alixander/connection-label-underline

allow underlines for connections

ci/release/changelogs/next.md

@@ -1,8 +1,10 @@
 #### Features 🚀
 
+- `style.underline` works on connections [#1836](https://github.com/terrastruct/d2/pull/1836)
+
 #### Improvements 🧹
 
 #### Bugfixes ⛑️
 
-- Fixes `null` being set on a nested shape not working in certain cases when connections also pointed to that shape [1830](https://github.com/terrastruct/d2/pull/1830)
-- Fixes edge case of bad import syntax crashing using d2 as a library [1829](https://github.com/terrastruct/d2/pull/1829)
+- Fixes `null` being set on a nested shape not working in certain cases when connections also pointed to that shape [#1830](https://github.com/terrastruct/d2/pull/1830)
+- Fixes edge case of bad import syntax crashing using d2 as a library [#1829](https://github.com/terrastruct/d2/pull/1829)

d2exporter/export.go

@@ -345,6 +345,9 @@ func toConnection(edge *d2graph.Edge, theme *d2themes.Theme) d2target.Connection
 	if edge.Style.Bold != nil {
 		connection.Bold, _ = strconv.ParseBool(edge.Style.Bold.Value)
 	}
+	if edge.Style.Underline != nil {
+		connection.Underline, _ = strconv.ParseBool(edge.Style.Underline.Value)
+	}
 	if theme != nil && theme.SpecialRules.Mono {
 		connection.FontFamily = "mono"
 	}

d2renderers/d2svg/d2svg.go

@@ -588,6 +588,9 @@ func drawConnection(writer io.Writer, labelMaskID string, connection d2target.Co
 		} else if connection.Italic {
 			fontClass += "-italic"
 		}
+		if connection.Underline {
+			fontClass += " text-underline"
+		}
 		if connection.Fill != color.Empty {
 			rectEl := d2themes.NewThemableElement("rect")
 			rectEl.X, rectEl.Y = labelTL.X, labelTL.Y

e2etests/testdata/txtar.txt

@@ -164,3 +164,9 @@ monsters: {
 }
 
 costumes.monster -> monsters.id
+
+-- connection-underline --
+
+a -> b: hi {
+  style.underline: true
+}