fix(logger): Keep falsy causes and literal % in error messages

.craft.yml

@@ -1,4 +1,4 @@
-minVersion: "2.33.0"
+minVersion: "3.5.0"
 workspaces:
   packages/cli:
     changelog:

packages/logger/src/message.ts

@@ -31,7 +31,7 @@ function formatError(error: ErrorLike, depth: number, stack: boolean): string {
   let cause = "";
   if (isErrorLike(error.cause)) {
     cause = `${stack ? "\n\n" : " "}${formatError(error.cause, depth + 1, stack)}`;
-  } else if (error.cause) {
+  } else if ("cause" in error) {
     cause = `${stack ? `\n\n${"  ".repeat(depth + 1)}` : " "}[cause]: ${formatWithOptions(INSPECT_OPTIONS, error.cause)}`;
   }
   if (!stack) {
@@ -57,8 +57,11 @@ export function formatMessage(
   args: readonly unknown[],
   { stack }: { stack: boolean },
 ): string {
-  return formatWithOptions(
-    INSPECT_OPTIONS,
-    ...args.map((arg) => (isErrorLike(arg) ? formatError(arg, 0, stack) : arg)),
+  const formatted = args.map((arg) =>
+    isErrorLike(arg) ? formatError(arg, 0, stack) : arg,
   );
+  // An error is not a format string, so `%s` in its message stays literal.
+  return isErrorLike(args[0])
+    ? formatWithOptions(INSPECT_OPTIONS, "%s", ...formatted)
+    : formatWithOptions(INSPECT_OPTIONS, ...formatted);
 }

packages/logger/test/logger.test.ts

@@ -468,4 +468,31 @@ describe("sentryReporter", () => {
       "Upload failed: Request failed [cause]: socket hang up",
     );
   });
+
+  test("keeps causes that are falsy", () => {
+    const { calls, sentryLogger } = fakeSentryLogger();
+    const logger = createLogger({ reporters: [sentryReporter(sentryLogger)] });
+    for (const cause of [0, "", false, null, undefined]) {
+      logger.error(new Error("Failed", { cause }));
+    }
+    logger.error(new Error("No cause"));
+    expect(calls.map(([, message]) => message)).toEqual([
+      "Failed [cause]: 0",
+      "Failed [cause]: ",
+      "Failed [cause]: false",
+      "Failed [cause]: null",
+      "Failed [cause]: undefined",
+      "No cause",
+    ]);
+  });
+
+  test("does not read an error's message as a format string", () => {
+    const { calls, sentryLogger } = fakeSentryLogger();
+    createLogger({ reporters: [sentryReporter(sentryLogger)] }).error(
+      new Error("Bad value %s"),
+      "extra",
+      { id: 1 },
+    );
+    expect(calls[0]?.[1]).toBe("Bad value %s extra { id: 1 }");
+  });
 });