fix: improve rendering of binary and json fields (#42)

Author: cmoog

src/controller.ts

@@ -140,17 +140,29 @@ function getMaxRows(): number {
   return maxRows ?? fallbackMaxRows;
 }
 
-function escapeNewline(a: string | number | null): string | number | null {
-  if (typeof a === 'string') {
-    return a.replace(/\n/g, '\\n').replace(/\r/g, '\\r');
+function serializeCell(a: any): any {
+  try {
+    // serialize buffers as hex strings
+    if (Buffer.isBuffer(a)) {
+      return `0x${a.toString('hex')}`;
+    }
+    // attempt to serialize all remaining "object" values as JSON
+    if (typeof a === 'object') {
+      return JSON.stringify(a);
+    }
+    if (typeof a === 'string') {
+      return a.replace(/\n/g, '\\n').replace(/\r/g, '\\r');
+    }
+    return a;
+  } catch {
+    return a;
   }
-  return a;
 }
 
 function markdownRow(row: Row): string {
   const middle = Object.entries(row)
     .map((pair) => pair[1])
-    .map(escapeNewline)
+    .map(serializeCell)
     .join(' | ');
   return `| ${middle} |`;
 }

src/driver.ts

@@ -19,7 +19,7 @@ export type ExecutionResult = TabularResult[];
 export type TabularResult = Row[];
 
 // Row represents an arbitrary map of data with marshallable values.
-export type Row = { [key: string]: string | number | null };
+export type Row = { [key: string]: any };
 
 // Conn is an abstraction over driver-specific connection interfaces.
 interface Conn {