feat(core): replace instruction checkpoints with value-delta sync (#36254)

packages/core/test/lib/instructions.ts

@@ -0,0 +1,43 @@
+import { Effect, Option, Schema } from "effect"
+import { Instructions } from "@opencode-ai/core/instructions"
+
+export interface State {
+  readonly values: Readonly<Record<string, Schema.Json>>
+}
+
+export const state = (values: Readonly<Record<string, Schema.Json>>): State => ({ values })
+
+const hashes = (values: Readonly<Record<string, Schema.Json>>): Instructions.Values =>
+  Object.fromEntries(Object.entries(values).map(([key, value]) => [key, Instructions.hash(value)]))
+
+export const readInitial = (instructions: Instructions.Instructions) =>
+  Effect.gen(function* () {
+    const admission = yield* Instructions.read(instructions).pipe(Effect.flatMap(Instructions.diff))
+    const current = state(
+      Object.fromEntries(
+        Object.entries(admission.delta).flatMap(([key, hash]) =>
+          hash === "removed" ? [] : [[key, admission.blobs[hash]]],
+        ),
+      ),
+    )
+    return { ...current, text: Instructions.renderInitial(instructions, current.values) }
+  })
+
+export const readUpdate = (instructions: Instructions.Instructions, previous: State) =>
+  Effect.gen(function* () {
+    const admission = yield* Instructions.read(instructions).pipe(
+      Effect.flatMap((observed) => Instructions.diff(observed, hashes(previous.values))),
+    )
+    const delta = Object.fromEntries(
+      Object.entries(admission.delta).map(([key, hash]) => [
+        key,
+        hash === "removed" ? Option.none() : Option.some(admission.blobs[hash]),
+      ]),
+    ) as Readonly<Record<string, Option.Option<Schema.Json>>>
+    const values = Instructions.applyDelta(previous.values, delta)
+    return {
+      values,
+      text: Instructions.renderUpdate(instructions, previous.values, delta),
+      changed: Object.keys(admission.delta).length > 0,
+    }
+  })