From 4e57c85f628c62094d805a604772ca7eb48a8cc1 Mon Sep 17 00:00:00 2001
From: Devon Stewart <devon.stewart@repl.it>
Date: Thu, 14 Nov 2024 11:36:03 -0800
Subject: [PATCH] Do a dance to handle the docker "hijack" message

---
 impls/node-protocolv2/client.ts | 19 ++++++++++++++++++-
 impls/node/client.ts            | 19 ++++++++++++++++++-
 impls/python/client.py          | 11 ++++++++++-
 3 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/impls/node-protocolv2/client.ts b/impls/node-protocolv2/client.ts
index fcba135..94137b5 100644
--- a/impls/node-protocolv2/client.ts
+++ b/impls/node-protocolv2/client.ts
@@ -71,7 +71,24 @@ const handles = new Map<
 >();
 
 for await (const line of rl) {
-  const { id, init, payload, proc } = JSON.parse(line);
+  const { id, init, payload, proc } = (() => {
+    try {
+      return JSON.parse(line);
+    } catch (e) {
+      // Sometimes docker injects this into the stream:
+      // {"hijack":true,"stream":true,"stdin":true,"stdout":true,"stderr":true}{"type": "invoke", ...
+      const match = e.message.match(/line (\d*) column (\d*)/);
+      if (!!match) {
+        const offset = parseInt(match['2'], 10);
+        const first = JSON.parse(line.substring(0, offset));
+        assert(
+          'hijack' in first,
+          'The only syntax errors that we expect are that Docker jams stuff into the stream',
+        );
+        return JSON.parse(line.substring(offset));
+      }
+    }
+  })();
 
   switch (proc) {
     case 'kv.set': {
diff --git a/impls/node/client.ts b/impls/node/client.ts
index 08da044..d97225c 100644
--- a/impls/node/client.ts
+++ b/impls/node/client.ts
@@ -61,7 +61,24 @@ const rl = readline.createInterface({
 
 const handles = new Map<string, Pushable<unknown>>();
 for await (const line of rl) {
-  const { id, init, payload, proc } = JSON.parse(line);
+  const { id, init, payload, proc } = (() => {
+    try {
+      return JSON.parse(line);
+    } catch (e) {
+      // Sometimes docker injects this into the stream:
+      // {"hijack":true,"stream":true,"stdin":true,"stdout":true,"stderr":true}{"type": "invoke", ...
+      const match = e.message.match(/line (\d*) column (\d*)/);
+      if (!!match) {
+        const offset = parseInt(match['2'], 10);
+        const first = JSON.parse(line.substring(0, offset));
+        assert(
+          'hijack' in first,
+          'The only syntax errors that we expect are that Docker jams stuff into the stream',
+        );
+        return JSON.parse(line.substring(offset));
+      }
+    }
+  })();
 
   switch (proc) {
     case 'kv.set': {
diff --git a/impls/python/client.py b/impls/python/client.py
index 116aa7c..289c185 100644
--- a/impls/python/client.py
+++ b/impls/python/client.py
@@ -71,7 +71,16 @@ async def process_commands():
             if not line:
                 break
 
-            action = json.loads(line)
+            try:
+                action = json.loads(line)
+            except json.JSONDecodeError as e:
+                # Sometimes docker injects this into the stream:
+                # {"hijack":true,"stream":true,"stdin":true,"stdout":true,"stderr":true}{"type": "invoke", ...
+                offset = e.colno - 1
+                first = json.loads(line[0:offset])
+                assert "hijack" in first
+                action = json.loads(line[offset:])
+
             if not action:
                 print("FATAL: invalid command", line)
                 sys.exit(1)