fix: support jest transformer that directly returns string

components/transformer-jest/node/index.mjs

@@ -49,18 +49,26 @@ const loadDispatchingEntry = ([pattern, { specifier, options }]) => [
   },
 ];
 
-const sanitizeSource = ({ code = null, map = null }, specifier) => {
-  assert(
-    !logErrorWhen(
-      typeof code !== "string",
-      "Transformer at %j should return an object whose code property is a string, got: %o",
-      specifier,
-      code,
-    ),
-    "Transformer should return an object whose code property is a string",
-    ExternalAppmapError,
-  );
-  return { code, map };
+const sanitizeSource = (source, specifier) => {
+  // This is no documented by transformers can directly
+  // return a string rather than an object.
+  // This is the case for `[email protected]`.
+  if (typeof source === "string") {
+    return { code: source, map: null };
+  } else {
+    const { code = null, map = null } = source;
+    assert(
+      !logErrorWhen(
+        typeof code !== "string",
+        "Transformer at %j should return an object whose code property is a string, got: %o",
+        specifier,
+        code,
+      ),
+      "Transformer should return an object whose code property is a string",
+      ExternalAppmapError,
+    );
+    return { code, map };
+  }
 };
 
 const transform = (
@@ -112,6 +120,7 @@ export const compileCreateTransformer = (configuration) => {
             );
             source = sanitizeSource(
               transformer.process(content, path, options),
+              specifier,
             );
             break;
           }

components/transformer-jest/node/index.test.mjs

@@ -18,9 +18,9 @@ const {
   Reflect: { get },
 } = globalThis;
 
-//////////////////////////////////////////////
-// CJS && No SourceMap && With processAsync //
-//////////////////////////////////////////////
+///////////////////////////////////////////////////////////////
+// CJS && No SourceMap && With processAsync && String Source //
+///////////////////////////////////////////////////////////////
 
 {
   const specifier = toAbsoluteUrl(`${getUuid()}.cjs`, getTmpUrl());
@@ -34,14 +34,8 @@ const {
           createTransformer: (options) => {
             assertEqual(options, "options");
             return {
-              process: (content, path, options) => ({
-                code: content + content,
-                map: null,
-              }),
-              processAsync: (content, path, options) => Promise.resolve({
-                code: content + content,
-                map: null,
-              }),
+              process: (content, path, options) => content + content,
+              processAsync: (content, path, options) => content + content,
             };
           },
         },
@@ -120,9 +114,9 @@ const {
   }
 }
 
-///////////////////////////////////////////////
-// ESM && With Source Map && No processAsync //
-///////////////////////////////////////////////
+////////////////////////////////////////////////////////////////
+// ESM && With Source Map && No processAsync && Object Source //
+////////////////////////////////////////////////////////////////
 
 {
   const specifier = toAbsoluteUrl(`${getUuid()}.js`, getTmpUrl());