Applying a text data set re-renders the type layer instead of blanking it (#990) (#1025)

apply_to_doc replaced a text-replacement variable's text and set the layer's
render cache to None, but nothing rebuilt it. The compositor draws a type
layer from that cache, so the text vanished from the canvas after
image.applyDataSet and from every file written by
file.export.dataSetsAsFiles. The layer is now re-rendered with
type_cmds::refresh, as type.edit does.

crates/engine/src/variables_cmds.rs

@@ -164,13 +164,16 @@ fn apply_to_doc(doc: &mut Document, vars: &Variables, set: &DataSet) -> Result<(
                 }
             }
             (VarKind::TextReplacement, VarValue::Text(text)) => {
+                let snapshot = doc.clone();
                 if let Some(l) = doc.layer_mut(def.layer)
                     && let LayerContent::Text(t) = &mut l.content
                 {
                     t.text = text.clone();
-                    t.cache = None; // force re-render
                     t.runs.clear(); // re-flow as one run from the summary style
                     t.paragraphs.clear();
+                    // The compositor draws a type layer from its cache: clearing it left the
+                    // layer blank until some other edit re-rendered it (#990).
+                    crate::type_cmds::refresh(&snapshot, t);
                 }
             }
             (VarKind::PixelReplacement { method, align, clip }, VarValue::Pixels(path)) => {

crates/engine/src/variables_cmds/tests.rs

@@ -190,3 +190,25 @@ fn pixel_replacement_changes_the_layer() {
         assert!(b > r, "replacement is blue-ish: {rgba:?}");
     }
 }
+
+#[test]
+fn applied_text_is_rendered_in_the_document_and_in_exports() {
+    // Applying a text value cleared the type layer's render cache and nothing rebuilt it, so the
+    // text vanished from the canvas and from every exported file (#990).
+    let mut s = Session::new();
+    s.execute("file.new", json!({"width": 200, "height": 60, "background": "white"})).unwrap();
+    let id = s.execute("type.create", json!({"x": 4, "y": 40, "text": "HELLO", "size": 32, "color": "#000000"})).unwrap()["layer"].clone();
+    let dark = |d: &Document| photocraft_compose::render(d, d.bounds()).px.iter().filter(|p| p[0] < 0.5).count();
+    assert!(dark(doc(&s)) > 0);
+    s.execute("image.variables.define", json!({"defs": [{"name": "headline", "layer": id, "type": "textReplacement"}]})).unwrap();
+    s.execute("image.variables.dataSets", json!({"dataSets": [{"name": "row1", "values": [{"variable": "headline", "kind": "text", "value": "BYE"}]}]}))
+        .unwrap();
+    let dir = tmp("text-export");
+    let out = s.execute("file.export.dataSetsAsFiles", json!({"dir": dir, "format": "png"})).unwrap();
+    let path = out["files"][0].as_str().unwrap();
+    let exported = photocraft_io::import(path, &std::fs::read(path).unwrap()).unwrap().document;
+    assert!(dark(&exported) > 0, "the exported row keeps its text");
+    s.execute("image.applyDataSet", json!({"name": "row1"})).unwrap();
+    assert!(dark(doc(&s)) > 0, "the applied text is drawn");
+    let _ = std::fs::remove_dir_all(&dir);
+}