Catch exit() errors

mdaines · Jun 15, 2023 · 4fb4276 · 4fb4276
1 parent 28f88ef
commit 4fb4276
Show file tree

Hide file tree

Showing 3 changed files with 31 additions and 4 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+* Catch the error Emscripten throws when exit() is called.
+
 * Don't add an error message about no valid graphs in input.
 
 * Improve error message handling when an error reported from agerr has multiple lines.

diff --git a/src/viz.mjs b/src/viz.mjs
@@ -38,6 +38,10 @@ function parseAgerrMessages(messages) {
   return result;
 }
 
+function parseErrorMessages(module) {
+  return parseAgerrMessages(module["agerrMessages"]).concat(parseStderrMessages(module["stderrMessages"]));
+}
+
 function render(module, src, options) {
   let srcPointer, resultPointer;
 
@@ -53,21 +57,29 @@ function render(module, src, options) {
 
     resultPointer = module.ccall("viz_render_string", "number", ["number", "string", "string"], [srcPointer, options.format, options.engine]);
 
-    const errors = parseAgerrMessages(module["agerrMessages"]).concat(parseStderrMessages(module["stderrMessages"]));
-
     if (resultPointer === 0) {
       return {
         status: "failure",
         output: undefined,
-        errors
+        errors: parseErrorMessages(module)
       };
     }
 
     return {
       status: "success",
       output: module.UTF8ToString(resultPointer),
-      errors
+      errors: parseErrorMessages(module)
     };
+  } catch (error) {
+    if (/^exit\(\d+\)/.test(error)) {
+      return {
+        status: "failure",
+        output: undefined,
+        errors: parseErrorMessages(module)
+      };
+    } else {
+      throw error;
+    }
   } finally {
     if (srcPointer) {
       module.ccall("free", "number", ["number"], [srcPointer]);

diff --git a/test/standalone.test.mjs b/test/standalone.test.mjs
@@ -232,6 +232,19 @@ describe("standalone", function() {
         ]
       });
     });
+
+    it("returns an error if exit() is called", function() {
+      const result = viz.render("graph { a[label=<>] }");
+
+      assert.deepStrictEqual(result,{
+        status: "failure",
+        output: undefined,
+        errors: [
+          { level: "error", message: "syntax error in line 1" },
+          { level: "error", message: "... <HTML></HTML> ..." }
+        ]
+      });
+    });
   });
 
   describe("graphvizVersion", function() {