add test for binary bson

Author: clezag

infrastructure/raw-writer-2/calls.http

@@ -11,6 +11,7 @@
 @ts6 = 2026-04-02T10:05:00Z
 @ts7 = 2026-04-02T10:06:00Z
 @ts8 = 2026-04-02T10:07:00Z
+@ts9 = 2026-04-02T10:08:00Z
 
 
 # ─── Health checks ────────────────────────────────────────────────────────────
@@ -66,9 +67,18 @@ User-Agent: calls-http/test
 
 ###
 
-### Small BSON (invalid) — malformed JSON with application/bson content-type (→ Mongo, binary field; bytes stored as-is)
-# The service stores whatever bytes it receives; BSON/JSON validation is the consumer's job.
-POST {{host}}/raw-writer-test/small-bson-invalid/{{ts5}}
+### Small BSON (binary) — actual binary BSON bytes with application/bson content-type (→ Mongo, parsed as bson.M)
+# testdata/small.bson is generated by ./testdata/generate.sh
+POST {{host}}/raw-writer-test/small-bson-binary/{{ts5}}
+Content-Type: application/bson
+User-Agent: calls-http/test
+
+< ./testdata/small.bson
+
+###
+
+### Small BSON (invalid) — malformed bytes, neither JSON nor BSON (→ Mongo, stored as raw binary)
+POST {{host}}/raw-writer-test/small-bson-invalid/{{ts9}}
 Content-Type: application/bson
 User-Agent: calls-http/test
 

infrastructure/raw-writer-2/testdata/.gitignore

@@ -1,3 +1,4 @@
 small.bin
+small.bson
 large.json
 large.bin

infrastructure/raw-writer-2/testdata/generate.sh

@@ -13,6 +13,25 @@ cd "$(dirname "$0")"
 printf '\xDE\xAD\xBE\xEF' > small.bin
 echo "created small.bin (4 bytes)"
 
+# small.bson — binary BSON encoding of {"hello":"world","value":42} (exercises the binary BSON path)
+python3 -c "
+import struct, sys
+
+def bson_string(key, val):
+    k = key.encode() + b'\x00'
+    v = val.encode() + b'\x00'
+    return b'\x02' + k + struct.pack('<i', len(v)) + v
+
+def bson_int32(key, val):
+    k = key.encode() + b'\x00'
+    return b'\x10' + k + struct.pack('<i', val)
+
+body = bson_string('hello', 'world') + bson_int32('value', 42)
+doc = struct.pack('<i', 4 + 1 + len(body)) + body + b'\x00'
+sys.stdout.buffer.write(doc)
+" > small.bson
+echo "created small.bson ($(wc -c < small.bson) bytes)"
+
 # large.json — ~6 MB JSON array (exercises the large compressible path → S3 + zstd)
 python3 -c "
 import json, sys