fix: rendering in typst

src/export/typst/diagnostic.rs

@@ -1031,6 +1031,17 @@ fn render(
     }
 
     let mut warnings = Vec::new();
+    for (slot, body) in &bodies {
+        if crate::markup::needs_chem_import(&template.source, body) {
+            warnings.push(format!(
+                "the `{}` slot carries a chemical formula, but the template {} does not import \
+                 whalogen, so Typst will stop at `unknown variable: ce`; add `{}`",
+                slot.as_str(),
+                template.origin,
+                crate::markup::CHEM_IMPORT
+            ));
+        }
+    }
     if template.is_inert() {
         warnings.push(format!(
             "the template {} declares no coursebank markers, so the report is empty; add `// \
@@ -1213,6 +1224,42 @@ mod tests {
         }
     }
 
+    #[test]
+    fn report_markup_takes_the_same_path_as_a_paper() {
+        for source in [
+            "$\\ce{H2O <=> H+ + OH-}$",
+            "the backbone $\\ce{-C=O}$ group",
+            "$K_w = [\\text{H}^+][\\text{OH}^-]$",
+            "see @fig:x where x < y",
+            "costs \\$5, and just $5",
+        ] {
+            let expected = crate::markup::to_typst(source);
+            assert_eq!(
+                markup_value(source, true).to_typst(0),
+                format!("[{expected}]"),
+                "content mode diverged on {source:?}"
+            );
+            assert_eq!(
+                markup_value(source, false).to_typst(0),
+                Value::str(expected).to_typst(0),
+                "string mode diverged on {source:?}"
+            );
+        }
+    }
+
+    #[test]
+    fn a_report_carrying_chemistry_names_a_template_missing_the_import() {
+        let body = "#let cb-data = (stem: [#ce(\"H2O\")])";
+        assert!(crate::markup::needs_chem_import(
+            "#import \"@preview/mitex:0.2.7\": mi\n// coursebank:data\n",
+            body
+        ));
+        assert!(!crate::markup::needs_chem_import(
+            crate::markup::CHEM_IMPORT,
+            body
+        ));
+    }
+
     #[test]
     fn the_headline_leads_with_the_distribution() {
         let lines = headline(&empty_cohort());