Add a pretty printer for snac debugging

DrewML · Dec 31, 2020 · d29ef6d · d29ef6d
1 parent 42304f3
commit d29ef6d
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Showing 3 changed files with 59 additions and 2 deletions.
diff --git a/src/BossServer/index.ts b/src/BossServer/index.ts
@@ -10,7 +10,7 @@ import {
     ssiLimitsSnac,
 } from './serverSnacs';
 import assert from 'assert';
-import { parseSnac, matchSnac } from '../snacUtils';
+import { parseSnac, matchSnac, prettyPrintSnac } from '../snacUtils';
 import { UserClass, UserStatus } from './constants';
 
 export class BossServer extends OscarServer {
@@ -75,7 +75,8 @@ export class BossServer extends OscarServer {
                 });
             }
 
-            console.log('boss unhandled data flap: ', flap);
+            console.log('BOSS: unhandled snac:');
+            console.log(prettyPrintSnac(snac));
         });
 
         oscarSocket.onFlap(FlapType.ERROR, (flap) => {

diff --git a/src/buf.ts b/src/buf.ts
@@ -1,5 +1,8 @@
 import { endianness } from 'os';
 
+const GREEN_TEXT = '\x1b[32m';
+const RESET_TEXT = '\x1b[0m';
+
 const isLE = endianness() === 'LE';
 
 /**
@@ -11,3 +14,37 @@ export function uint16(values: number | number[]) {
     if (isLE) buf.swap16();
     return buf;
 }
+
+/**
+ * @summary Pretty print a Buffer as hex-encoded bytes
+ */
+export function prettyPrint(buffer: Buffer, maxBytesPerLine = 10) {
+    const hexStr = buffer.toString('hex');
+    // split hex string into byte-sized chunks
+    const bytes = hexStr.match(/.{1,2}/g);
+
+    if (!bytes) return '';
+
+    let output = '';
+    let itemCount = 0;
+
+    while (bytes.length) {
+        const byte = bytes.shift();
+        output += `0x${byte}`;
+
+        if (itemCount + 1 === maxBytesPerLine) {
+            // reset line item counter
+            itemCount = 0;
+            // drop to a new line
+            output += '\n';
+        } else {
+            if (bytes.length) {
+                // not the last item in the row, so add whitespace padding
+                output += ' ';
+            }
+            itemCount++;
+        }
+    }
+
+    return `${GREEN_TEXT}${output}${RESET_TEXT}`;
+}
diff --git a/src/snacUtils.ts b/src/snacUtils.ts
@@ -1,5 +1,9 @@
 import { Snac } from './types';
 import { SNACS } from './constants';
+import { prettyPrint } from './buf';
+
+const BOLD_TEXT = '\x1b[1m';
+const RESET_TEXT = '\x1b[0m';
 
 /**
  * @summary Determines whether a Snac is a specific
@@ -54,3 +58,18 @@ export function parseSnac(rawSnac: Buffer): Snac {
         data: rawSnac.subarray(10),
     };
 }
+
+/**
+ * @summary Pretty Print a parsed SNAC
+ */
+export function prettyPrintSnac(snac: Snac) {
+    const printedData = prettyPrint(snac.data);
+    const family = `0x${snac.family.toString(16)}`;
+    const subtype = `0x${snac.subtype.toString(16)}`;
+
+    return `${BOLD_TEXT}Family:${RESET_TEXT} ${family}
+${BOLD_TEXT}Subtype:${RESET_TEXT} ${subtype}
+${BOLD_TEXT}Flags:${RESET_TEXT} ${snac.flags}
+${BOLD_TEXT}Request ID:${RESET_TEXT} ${snac.requestID}
+${BOLD_TEXT}Payload:${RESET_TEXT}\n${printedData}\n`;
+}