fix(demo): make demos robust against bigints in JSON.stringify

Author: michaelfig

packages/swingset-runner/demo/exchangeBenchmark/printLog.js

@@ -1,7 +1,14 @@
+function bigintReplacer(_, arg) {
+  if (typeof arg === 'bigint') {
+    return Number(arg);
+  }
+  return arg;
+}
+
 export function makePrintLog() {
   return function printLog(...args) {
     const rendered = args.map(arg =>
-      typeof arg === 'string' ? arg : JSON.stringify(arg),
+      typeof arg === 'string' ? arg : JSON.stringify(arg, bigintReplacer),
     );
     console.log(rendered.join(''));
   };

packages/swingset-runner/demo/swapBenchmark/printLog.js

@@ -1,7 +1,14 @@
+function bigintReplacer(_, arg) {
+  if (typeof arg === 'bigint') {
+    return Number(arg);
+  }
+  return arg;
+}
+
 export function makePrintLog() {
   return function printLog(...args) {
     const rendered = args.map(arg =>
-      typeof arg === 'string' ? arg : JSON.stringify(arg),
+      typeof arg === 'string' ? arg : JSON.stringify(arg, bigintReplacer),
     );
     console.log(rendered.join(''));
   };

packages/swingset-runner/demo/zoeTests/printLog.js

@@ -1,7 +1,14 @@
+function bigintReplacer(_, arg) {
+  if (typeof arg === 'bigint') {
+    return Number(arg);
+  }
+  return arg;
+}
+
 export function makePrintLog() {
   return function printLog(...args) {
     const rendered = args.map(arg =>
-      typeof arg === 'string' ? arg : JSON.stringify(arg),
+      typeof arg === 'string' ? arg : JSON.stringify(arg, bigintReplacer),
     );
     console.log(rendered.join(''));
   };