Recognise a forwarded message (§6.16)

An inbound forward is shown as one rather than as the sender's own words. Both flag shapes accepted, like ctl: org.json's optBoolean does not coerce a number, so an engine reading one shape would silently miss every forward the other two send. ⚠️ The subtle one: Content.text returns raw bytes with no envelope at all when there is no id, reply or link to carry. A forward that was not counted in that condition would lose its flag and arrive looking like the sender's own composition — so is part of the test for whether an envelope is needed, not just a field inside it. Codec only. Originating a forward needs the transcript work in #10. Refs paulhitt/flamenet-messenger-ios#28 Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-09-02 15:50:17 -04:00
parent 00c043918f
commit 01e6d6fe6d
3 changed files with 130 additions and 3 deletions
@@ -0,0 +1,96 @@
+package io.flamenet.e2e
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+import org.json.JSONObject
+
+/**
+ * Passing a message on without passing on where it came from (§6.16).
+ *
+ * ⚠️ **The codec half.** The Android app cannot forward yet — that needs the
+ * transcript work in #10 — but it must already understand an envelope the
+ * iPhone app sends, so a forwarded message arrives as a message and not as
+ * something the reader is told nothing about.
+ */
+class ForwardWithoutProvenanceTest {
+
+    @Test
+    fun `a forwarded message is marked as forwarded`() {
+        val content = Content.parse(Content.text("meet at 6", forwarded = true))
+        assertTrue(content.isForwarded)
+        assertEquals("meet at 6", content.text)
+    }
+
+    @Test
+    fun `an ordinary message is not marked forwarded`() {
+        assertFalse(Content.parse(Content.text("meet at 6")).isForwarded)
+    }
+
+    /**
+     * 🔴 The whole point: the envelope says THAT it was forwarded and nothing
+     * about who wrote it or what it answered.
+     */
+    @Test
+    fun `the envelope carries no author and no reply chain`() {
+        val wire = Content.text("meet at 6", forwarded = true)
+        assertFalse(wire.contains("author"), "the envelope carries an author: $wire")
+        assertFalse(wire.contains("\"re\""), "the envelope carries a reply chain: $wire")
+        assertNull(Content.parse(wire).about)
+    }
+
+    /**
+     * ⚠️ `1`, not `true` — §6.10's shape. `org.json`'s optBoolean does not
+     * coerce a number, so an engine that read only one shape would silently
+     * miss every forward the other two engines send.
+     */
+    @Test
+    fun `both flag shapes are accepted`() {
+        val asNumber = Content.text("hi", forwarded = true)
+        assertTrue(asNumber.contains("\"fwd\":1"), "wrote the wrong shape: $asNumber")
+        assertTrue(Content.parse(asNumber).isForwarded)
+
+        val asBool = asNumber.replace("\"fwd\":1", "\"fwd\":true")
+        assertTrue(Content.parse(asBool).isForwarded,
+            "an engine writing `true` would have its forwards read as ordinary messages")
+    }
+
+    /** ⚠️ A forward is still a message: it renders, unlike control traffic. */
+    @Test
+    fun `a forwarded message is still renderable`() {
+        assertTrue(Content.parse(Content.text("meet at 6", forwarded = true)).isRenderable)
+    }
+
+    /** The flag rides an attachment too — a forwarded photo is still a forward. */
+    @Test
+    fun `a forwarded attachment keeps the flag`() {
+        val ref = Attachment.Ref(
+            kind = Attachment.IMAGE, id = "a".repeat(64),
+            key = ByteArray(32) { 1 }, digest = ByteArray(32) { 2 },
+            bytes = 1024, mime = "image/jpeg", width = 100, height = 100,
+            duration = 0.0, expires = 0.0,
+        )
+        val content = Content.parse(
+            Content.attachment(ref, caption = "look", forwarded = true))
+        assertTrue(content.isForwarded)
+        assertEquals("look", content.text)
+    }
+
+    /** ⚠️ `fnc` first, like every other envelope. */
+    @Test
+    fun `the envelope starts with the marker`() {
+        assertTrue(Content.text("hi", forwarded = true).startsWith("{\"fnc\":1,"))
+    }
+
+    /**
+     * A missing flag is not a forward — the ordinary case, and the one that
+     * every message sent before today takes.
+     */
+    @Test
+    fun `an envelope with no flag is not a forward`() {
+        val json = JSONObject("""{"fnc":1,"kind":"text","caption":"hi"}""")
+        assertFalse(Content.parse(json.toString()).isForwarded)
+    }
+}