feat(context): compact successful write/edit tool results to receipts (#289)

A successful file_write/file_edit echoes the whole file body (+ diff) back in its tool result — up to ~30k chars, which pushed the traced Gemma4 request past its context window. The write already happened and its full output is durable in the event log/CAS; the model only needs a receipt that it landed. Replace each exit=0 write result with a one-line receipt (path + elision marker) in the context builder; reads, gate output, and nonzero-exit writes stay verbatim. Derived-only pass over the transcript — authoritative events are untouched, so it's replay-safe. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-20 18:17:42 +04:00
parent 04336308f5
commit f860d1b8af
2 changed files with 113 additions and 2 deletions
@@ -0,0 +1,72 @@
+import com.correx.core.context.builder.DefaultContextPackBuilder
+import com.correx.core.context.compression.DefaultContextCompressor
+import com.correx.core.context.model.ContextEntry
+import com.correx.core.context.model.ContextLayer
+import com.correx.core.context.model.EntryRole
+import com.correx.core.context.model.TokenBudget
+import com.correx.core.events.types.ContextEntryId
+import com.correx.core.events.types.ContextPackId
+import com.correx.core.events.types.SessionId
+import com.correx.core.events.types.StageId
+import kotlinx.coroutines.runBlocking
+import org.junit.jupiter.api.Assertions.assertFalse
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+
+// #289: a successful file_write/file_edit result echoes the whole file body back — it must be
+// compacted to a receipt so it can't blow the context window, while reads and failures stay full.
+class WriteReceiptCompactionTest {
+
+    private val builder = DefaultContextPackBuilder(DefaultContextCompressor())
+    private val bigBody = "x".repeat(20_000)
+
+    private fun call(sourceId: String, name: String, path: String) = ContextEntry(
+        id = ContextEntryId("call-$sourceId"),
+        layer = ContextLayer.L2,
+        content = """{"id":"$sourceId","function":{"name":"$name","arguments":"{\"path\":\"$path\"}"}}""",
+        sourceType = "assistantToolCall",
+        sourceId = sourceId,
+        tokenEstimate = 40,
+        role = EntryRole.ASSISTANT,
+    )
+
+    private fun result(sourceId: String, content: String) = ContextEntry(
+        id = ContextEntryId("res-$sourceId"),
+        layer = ContextLayer.L2,
+        content = content,
+        sourceType = "toolResult",
+        sourceId = sourceId,
+        tokenEstimate = content.length / 4,
+        role = EntryRole.TOOL,
+    )
+
+    private suspend fun build(entries: List<ContextEntry>) =
+        builder.build(ContextPackId("p"), SessionId("s"), StageId("st"), entries, TokenBudget(limit = 1_000_000))
+
+    @Test
+    fun `successful write result is compacted to a receipt`(): Unit = runBlocking {
+        val entries = listOf(
+            call("tc1", "file_write", "src/A.kt"),
+            result("tc1", "[file_write exit=0]\n$bigBody"),
+        )
+        val res = build(entries).layers.values.flatten().first { it.sourceType == "toolResult" }
+        assertFalse(res.content.contains(bigBody), "body should be elided from the receipt")
+        assertTrue(res.content.contains("src/A.kt"), "receipt names the path")
+        assertTrue(res.content.contains("body elided"), "receipt marks the elision")
+    }
+
+    @Test
+    fun `read results and failed writes are left verbatim`(): Unit = runBlocking {
+        val readBody = "[file_read exit=0]\n$bigBody"
+        val failBody = "ERROR: could not write src/B.kt"
+        val entries = listOf(
+            call("r1", "file_read", "src/A.kt"),
+            result("r1", readBody),
+            call("w1", "file_write", "src/B.kt"),
+            result("w1", failBody),
+        )
+        val results = build(entries).layers.values.flatten().filter { it.sourceType == "toolResult" }
+        assertTrue(results.any { it.content == readBody }, "read result stays verbatim")
+        assertTrue(results.any { it.content == failBody }, "failed write stays verbatim")
+    }
+}