feat: dynamically resolve AGENTS.md files from subdirectories as agent explores them (#10678)

packages/opencode/test/session/instruction.test.ts

@@ -0,0 +1,46 @@
+import { describe, expect, test } from "bun:test"
+import path from "path"
+import { InstructionPrompt } from "../../src/session/instruction"
+import { Instance } from "../../src/project/instance"
+import { tmpdir } from "../fixture/fixture"
+
+describe("InstructionPrompt.resolve", () => {
+  test("returns empty when AGENTS.md is at project root (already in systemPaths)", async () => {
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "AGENTS.md"), "# Root Instructions")
+        await Bun.write(path.join(dir, "src", "file.ts"), "const x = 1")
+      },
+    })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const system = await InstructionPrompt.systemPaths()
+        expect(system.has(path.join(tmp.path, "AGENTS.md"))).toBe(true)
+
+        const results = await InstructionPrompt.resolve([], path.join(tmp.path, "src", "file.ts"))
+        expect(results).toEqual([])
+      },
+    })
+  })
+
+  test("returns AGENTS.md from subdirectory (not in systemPaths)", async () => {
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(path.join(dir, "subdir", "AGENTS.md"), "# Subdir Instructions")
+        await Bun.write(path.join(dir, "subdir", "nested", "file.ts"), "const x = 1")
+      },
+    })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const system = await InstructionPrompt.systemPaths()
+        expect(system.has(path.join(tmp.path, "subdir", "AGENTS.md"))).toBe(false)
+
+        const results = await InstructionPrompt.resolve([], path.join(tmp.path, "subdir", "nested", "file.ts"))
+        expect(results.length).toBe(1)
+        expect(results[0].filepath).toBe(path.join(tmp.path, "subdir", "AGENTS.md"))
+      },
+    })
+  })
+})