snapshot of https://github.com/shadcn-ui/ui.git (main, 2026-09-15; blobs > 131072B omitted)

packages/helpers/src/core/lower.test.ts

@@ -0,0 +1,218 @@
+import { describe, expect, it } from "vitest"
+
+import { lowerEvents } from "./lower"
+import { chunkSteps } from "./test-utils"
+import type { TestData, TestTools } from "./test-utils"
+import { splitTextDeltas } from "./utils"
+
+describe("lowerEvents", () => {
+  it("places before-start sleeps ahead of the start chunk", () => {
+    const steps = lowerEvents(
+      [
+        { kind: "sleep", delayMs: 100, phase: "before-start" },
+        {
+          kind: "text",
+          id: "text-1",
+          text: "Hi",
+          options: { mode: "instant" },
+        },
+      ],
+      { delayMs: 0 }
+    )
+
+    expect(chunkSteps(steps)).toEqual([
+      "sleep",
+      "start",
+      "text-start",
+      "text-delta",
+      "text-end",
+      "finish",
+      "close",
+    ])
+  })
+
+  it("keeps later sleeps after the start chunk", () => {
+    const steps = lowerEvents(
+      [
+        { kind: "step-start" },
+        { kind: "sleep", delayMs: 100, phase: "after-start" },
+      ],
+      { delayMs: 0 }
+    )
+
+    expect(chunkSteps(steps)).toEqual([
+      "start",
+      "start-step",
+      "sleep",
+      "finish",
+      "close",
+    ])
+  })
+
+  it("omits delta sleeps when delayMs is undefined", () => {
+    const steps = lowerEvents(
+      [{ kind: "text", id: "text-1", text: "Hello there world" }],
+      { delayMs: undefined }
+    )
+
+    expect(chunkSteps(steps)).toEqual([
+      "start",
+      "text-start",
+      "text-delta",
+      "text-delta",
+      "text-delta",
+      "text-end",
+      "finish",
+      "close",
+    ])
+  })
+
+  it("splits streamed text into word deltas with sleeps", () => {
+    const steps = lowerEvents(
+      [{ kind: "text", id: "text-1", text: "Hello there world" }],
+      { delayMs: 25 }
+    )
+
+    expect(chunkSteps(steps)).toEqual([
+      "start",
+      "text-start",
+      "sleep",
+      "text-delta",
+      "sleep",
+      "text-delta",
+      "sleep",
+      "text-delta",
+      "text-end",
+      "finish",
+      "close",
+    ])
+    expect(
+      steps.flatMap((step) =>
+        step.kind === "chunk" && step.chunk.type === "text-delta"
+          ? [step.chunk.delta]
+          : []
+      )
+    ).toEqual(splitTextDeltas("Hello there world"))
+  })
+
+  it("emits a single delta in instant mode and none of the word sleeps when delay is zero", () => {
+    const steps = lowerEvents(
+      [
+        {
+          kind: "reasoning",
+          id: "reasoning-1",
+          text: "Thinking about it",
+          options: { mode: "instant" },
+        },
+      ],
+      { delayMs: 0 }
+    )
+
+    expect(chunkSteps(steps)).toEqual([
+      "start",
+      "reasoning-start",
+      "reasoning-delta",
+      "reasoning-end",
+      "finish",
+      "close",
+    ])
+  })
+
+  it("honors per-event delay overrides", () => {
+    const steps = lowerEvents(
+      [
+        {
+          kind: "text",
+          id: "text-1",
+          text: "Hi",
+          options: { mode: "instant", delayMs: 10 },
+        },
+      ],
+      { delayMs: 0 }
+    )
+
+    expect(chunkSteps(steps)).toEqual([
+      "start",
+      "text-start",
+      "sleep",
+      "text-delta",
+      "text-end",
+      "finish",
+      "close",
+    ])
+  })
+
+  it("closes after an error chunk without a finish", () => {
+    const steps = lowerEvents(
+      [
+        {
+          kind: "text",
+          id: "text-1",
+          text: "Hi",
+          options: { mode: "instant" },
+        },
+        { kind: "error", errorText: "Boom." },
+        { kind: "step-start" },
+      ],
+      { delayMs: 0 }
+    )
+
+    expect(chunkSteps(steps)).toEqual([
+      "start",
+      "text-start",
+      "text-delta",
+      "text-end",
+      "error",
+      "close",
+    ])
+  })
+
+  it("carries message metadata on the finish chunk", () => {
+    const steps = lowerEvents([], {
+      delayMs: 0,
+      messageMetadata: { model: "gpt-5" },
+    })
+    const finish = steps.find(
+      (step) => step.kind === "chunk" && step.chunk.type === "finish"
+    )
+
+    expect(finish).toMatchObject({
+      chunk: {
+        type: "finish",
+        finishReason: "stop",
+        messageMetadata: { model: "gpt-5" },
+      },
+    })
+  })
+
+  it("maps tool events to tool chunks", () => {
+    const steps = lowerEvents<unknown, TestData, TestTools>(
+      [
+        {
+          kind: "tool-input",
+          name: "getWeather",
+          toolCallId: "call-1",
+          input: { city: "SF" },
+        },
+        {
+          kind: "tool-output",
+          toolCallId: "call-1",
+          output: { temperature: 72 },
+        },
+        { kind: "tool-error", toolCallId: "call-1", errorText: "Down." },
+        { kind: "tool-denied", toolCallId: "call-1" },
+      ],
+      { delayMs: 0 }
+    )
+
+    expect(chunkSteps(steps)).toEqual([
+      "start",
+      "tool-input-available",
+      "tool-output-available",
+      "tool-output-error",
+      "tool-output-denied",
+      "finish",
+      "close",
+    ])
+  })
+})