feat(web): attach selected response text

apps/web/src/chatSelectionAnnotation.test.ts

@@ -0,0 +1,94 @@
+import { describe, expect, it } from "vite-plus/test";
+
+import {
+  appendChatSelectionAnnotationsToPrompt,
+  formatChatSelectionAnnotation,
+  parseChatSelectionMessageSegments,
+  stripAppendedChatSelectionAnnotations,
+  type ChatSelectionAnnotation,
+} from "./chatSelectionAnnotation";
+
+const annotation: ChatSelectionAnnotation = {
+  id: "selection-1",
+  selectedText: "Restart <the> adapter",
+  comment: "Why is this necessary?",
+};
+
+describe("chat selection annotations", () => {
+  it("round-trips selected text and comments without treating markup as tags", () => {
+    const prompt = appendChatSelectionAnnotationsToPrompt("Explain this", [annotation]);
+    const segments = parseChatSelectionMessageSegments(prompt);
+
+    expect(segments).toHaveLength(2);
+    expect(segments[0]).toEqual({
+      kind: "text",
+      id: "chat-selection-text:0",
+      text: "Explain this\n\n",
+    });
+    expect(segments[1]).toEqual({ kind: "selection", annotation });
+  });
+
+  it("supports multiple annotations", () => {
+    const second = {
+      ...annotation,
+      id: "selection-2",
+      comment: "Compare this",
+    };
+    const segments = parseChatSelectionMessageSegments(
+      appendChatSelectionAnnotationsToPrompt("", [annotation, second]),
+    );
+
+    expect(segments.filter((segment) => segment.kind === "selection")).toHaveLength(2);
+  });
+
+  it("keeps user-authored chat selection markup as message text", () => {
+    const userAuthoredMarkup = [
+      '<chat_selection id="example">',
+      "<selected_text>",
+      "this is just an example",
+      "</selected_text>",
+      "<user_comment>",
+      "please explain this format",
+      "</user_comment>",
+      "</chat_selection>",
+    ].join("\n");
+
+    expect(parseChatSelectionMessageSegments(userAuthoredMarkup)).toEqual([
+      { kind: "text", id: "chat-selection-text:0", text: userAuthoredMarkup },
+    ]);
+  });
+
+  it("does not let a user-authored opener swallow a following annotation", () => {
+    const prompt = appendChatSelectionAnnotationsToPrompt("Explain this literal <chat_selection>", [
+      annotation,
+    ]);
+
+    expect(parseChatSelectionMessageSegments(prompt)).toEqual([
+      {
+        kind: "text",
+        id: "chat-selection-text:0",
+        text: "Explain this literal <chat_selection>\n\n",
+      },
+      { kind: "selection", annotation },
+    ]);
+  });
+
+  it("does not emit a block for an empty annotation list", () => {
+    expect(appendChatSelectionAnnotationsToPrompt("Keep this", [])).toBe("Keep this");
+    expect(formatChatSelectionAnnotation(annotation)).toContain("<selected_text>");
+  });
+
+  it("preserves prompt whitespace when appending annotations", () => {
+    const prompt = "  Keep this  ";
+
+    expect(appendChatSelectionAnnotationsToPrompt(prompt, [annotation])).toBe(
+      `${prompt}\n\n${formatChatSelectionAnnotation(annotation)}`,
+    );
+  });
+
+  it("strips app-appended annotations while preserving message text", () => {
+    const prompt = appendChatSelectionAnnotationsToPrompt("Explain this", [annotation]);
+
+    expect(stripAppendedChatSelectionAnnotations(prompt)).toBe("Explain this\n\n");
+  });
+});

apps/web/src/chatSelectionAnnotation.ts

@@ -0,0 +1,128 @@
+import * as Schema from "effect/Schema";
+
+export const ChatSelectionAnnotationSchema = Schema.Struct({
+  id: Schema.String,
+  selectedText: Schema.String,
+  comment: Schema.String,
+});
+
+export type ChatSelectionAnnotation = typeof ChatSelectionAnnotationSchema.Type;
+
+export type ChatSelectionMessageSegment =
+  | { readonly kind: "text"; readonly id: string; readonly text: string }
+  | { readonly kind: "selection"; readonly annotation: ChatSelectionAnnotation };
+
+const CHAT_SELECTION_BLOCK_PATTERN =
+  /<chat_selection\b([^<>\n]*)>\s*<selected_text>\s*([\s\S]*?)\s*<\/selected_text>\s*<user_comment>\s*([\s\S]*?)\s*<\/user_comment>\s*<\/chat_selection>/g;
+const CHAT_SELECTION_ATTRIBUTE_PATTERN = /([a-zA-Z][a-zA-Z0-9_-]*)="([^"]*)"/g;
+const CHAT_SELECTION_APP_MARKER_NAME = "data-t3code-appended";
+const CHAT_SELECTION_APP_MARKER_VALUE = "true";
+const CHAT_SELECTION_APP_MARKER = `${CHAT_SELECTION_APP_MARKER_NAME}="${CHAT_SELECTION_APP_MARKER_VALUE}"`;
+
+function escapeXml(value: string): string {
+  return value
+    .replace(/&/g, "&amp;")
+    .replace(/</g, "&lt;")
+    .replace(/>/g, "&gt;")
+    .replace(/"/g, "&quot;");
+}
+
+function unescapeXml(value: string): string {
+  return value
+    .replace(/&quot;/g, '"')
+    .replace(/&gt;/g, ">")
+    .replace(/&lt;/g, "<")
+    .replace(/&amp;/g, "&");
+}
+
+function readId(rawAttributes: string, fallback: string): string {
+  for (const match of rawAttributes.matchAll(CHAT_SELECTION_ATTRIBUTE_PATTERN)) {
+    if (match[1] === "id" && match[2]) return unescapeXml(match[2]);
+  }
+  return fallback;
+}
+
+function isAppendedChatSelection(rawAttributes: string): boolean {
+  for (const match of rawAttributes.matchAll(CHAT_SELECTION_ATTRIBUTE_PATTERN)) {
+    if (
+      match[1] === CHAT_SELECTION_APP_MARKER_NAME &&
+      match[2] === CHAT_SELECTION_APP_MARKER_VALUE
+    ) {
+      return true;
+    }
+  }
+  return false;
+}
+
+export function formatChatSelectionAnnotation(annotation: ChatSelectionAnnotation): string {
+  return [
+    `<chat_selection id="${escapeXml(annotation.id)}" ${CHAT_SELECTION_APP_MARKER}>`,
+    "<selected_text>",
+    escapeXml(annotation.selectedText.trim()),
+    "</selected_text>",
+    "<user_comment>",
+    escapeXml(annotation.comment.trim()),
+    "</user_comment>",
+    "</chat_selection>",
+  ].join("\n");
+}
+
+export function appendChatSelectionAnnotationsToPrompt(
+  prompt: string,
+  annotations: ReadonlyArray<ChatSelectionAnnotation>,
+): string {
+  if (annotations.length === 0) return prompt;
+  const blocks = annotations.map(formatChatSelectionAnnotation).join("\n\n");
+  const trimmedPrompt = prompt.trim();
+  return trimmedPrompt.length > 0 ? `${prompt}\n\n${blocks}` : blocks;
+}
+
+export function parseChatSelectionMessageSegments(
+  value: string,
+): ReadonlyArray<ChatSelectionMessageSegment> {
+  const segments: ChatSelectionMessageSegment[] = [];
+  let cursor = 0;
+  let parsedIndex = 0;
+
+  for (const match of value.matchAll(CHAT_SELECTION_BLOCK_PATTERN)) {
+    const matchIndex = match.index ?? 0;
+    const beforeText = value.slice(cursor, matchIndex);
+    if (beforeText.length > 0) {
+      segments.push({ kind: "text", id: `chat-selection-text:${cursor}`, text: beforeText });
+    }
+
+    if (!isAppendedChatSelection(match[1] ?? "")) {
+      segments.push({ kind: "text", id: `chat-selection-text:${matchIndex}`, text: match[0] });
+      cursor = matchIndex + match[0].length;
+      continue;
+    }
+
+    const selectedText = unescapeXml(match[2] ?? "").trim();
+    if (selectedText.length === 0) {
+      segments.push({ kind: "text", id: `chat-selection-invalid:${matchIndex}`, text: match[0] });
+    } else {
+      segments.push({
+        kind: "selection",
+        annotation: {
+          id: readId(match[1] ?? "", `chat-selection:${parsedIndex}`),
+          selectedText,
+          comment: unescapeXml(match[3] ?? "").trim(),
+        },
+      });
+      parsedIndex += 1;
+    }
+    cursor = matchIndex + match[0].length;
+  }
+
+  const rest = value.slice(cursor);
+  if (rest.length > 0) {
+    segments.push({ kind: "text", id: `chat-selection-text:${cursor}`, text: rest });
+  }
+  return segments;
+}
+
+export function stripAppendedChatSelectionAnnotations(value: string): string {
+  return parseChatSelectionMessageSegments(value)
+    .flatMap((segment) => (segment.kind === "text" ? [segment.text] : []))
+    .join("");
+}