fix(web): paths pasted after @ keep their underscores

apps/web/src/components/ComposerPromptEditorTiptap.tsx

@@ -45,6 +45,7 @@ import {
   collapseExpandedComposerCursor,
   expandCollapsedComposerCursor,
   isCollapsedCursorAdjacentToInlineToken,
+  pastedPathQueryLength,
 } from "~/composer-logic";
 import {
   collectComposerPromptInlineTokens,
@@ -1412,6 +1413,9 @@ function ComposerPromptEditorTiptapInner(props: ComposerPromptEditorProps) {
             const offset = flatToMarkdown(map, pmToFlat(map, view.state.selection.from));
             if (offset > 0 && !/\s/.test(map.value[offset - 1]!)) text = ` ${text}`;
           }
+          const { $from } = view.state.selection;
+          const lineBefore = $from.parent.textBetween(0, $from.parentOffset, undefined, "\uFFFC");
+          const literalLength = literalText ? 0 : pastedPathQueryLength(lineBefore, text);
           const editorInstance = editorHolder.current;
           if (editorInstance) {
             // Inside a list item or quote, pasted block markup has nowhere to
@@ -1424,7 +1428,7 @@ function ComposerPromptEditorTiptapInner(props: ComposerPromptEditorProps) {
             insertMarkdownParagraphs(
               text,
               skillLabelFor,
-              { styling: richText, blocks: !nested, literalText },
+              { styling: richText, blocks: !nested, literalText, literalLength },
               (content) => {
                 // Tagged on the same transaction insertContent builds, so the
                 // paste is one undo step of its own.
@@ -1815,7 +1819,7 @@ function ComposerPromptEditorTiptapInner(props: ComposerPromptEditorProps) {
 function insertMarkdownParagraphs(
   value: string,
   skillLabelFor: (name: string) => SkillMeta,
-  options: { styling: boolean; blocks?: boolean; literalText?: boolean },
+  options: { styling: boolean; blocks?: boolean; literalText?: boolean; literalLength?: number },
   insertContent: (content: JSONContent[] | JSONContent) => void,
 ): void {
   const blocks = buildTiptapContent(value, skillLabelFor, options);

apps/web/src/composer-logic.ts

@@ -306,6 +306,17 @@ export function detectComposerTrigger(text: string, cursorInput: number): Compos
   };
 }
 
+/**
+ * Length of the leading part of `pasted` that continues an `@` path query
+ * typed at the end of `lineBefore`, the line's plain text up to the caret. A
+ * chip must read there as one non-space character, so it never passes for a
+ * typed `@path`.
+ */
+export function pastedPathQueryLength(lineBefore: string, pasted: string): number {
+  if (detectComposerTrigger(lineBefore, lineBefore.length)?.kind !== "path") return 0;
+  return /^\S*/.exec(pasted)![0].length;
+}
+
 /** Caret and trigger after replacing composer text and continuing at the end. */
 export function composerStateAtPromptEnd(
   text: string,

apps/web/src/composer-rich-text-doc.test.ts

@@ -6,7 +6,7 @@ import { EditorState, TextSelection } from "@tiptap/pm/state";
 import { splitBlockKeepMarks } from "@tiptap/pm/commands";
 import { describe, expect, it } from "vite-plus/test";
 
-import { collapseExpandedComposerCursor } from "./composer-logic";
+import { collapseExpandedComposerCursor, pastedPathQueryLength } from "./composer-logic";
 
 import {
   buildDocJson,
@@ -942,6 +942,88 @@ describe("pasting into a list item or quote", () => {
   });
 });
 
+describe("pasting into a path query", () => {
+  const skillLabelFor = (name: string) => ({ label: name, description: null });
+
+  // Inserts `pasted` at the end of a one-line prompt the way the composer's
+  // paste handler does. `prompt` may be a document, to place the caret after a chip.
+  function paste(prompt: string | ProseMirrorNode, pasted: string) {
+    const promptDoc =
+      typeof prompt === "string"
+        ? ProseMirrorNode.fromJSON(schema, buildDocJson(prompt, skillLabelFor))
+        : prompt;
+    const line = promptDoc.lastChild!;
+    const lineBefore = line.textBetween(0, line.content.size, undefined, "\uFFFC");
+    const literalLength = pastedPathQueryLength(lineBefore, pasted);
+    const blocks = buildTiptapContent(pasted, skillLabelFor, { literalLength });
+    const [first, ...rest] = blocks.map((block) => ProseMirrorNode.fromJSON(schema, block));
+    const head = promptDoc.lastChild!.content.append(first!.content);
+    const doc = schema.node("doc", null, [first!.copy(head), ...rest]);
+    doc.check();
+    return doc;
+  }
+
+  function boldText(doc: ProseMirrorNode) {
+    const bold: string[] = [];
+    doc.descendants((node) => {
+      if (node.isText && node.marks.some((mark) => mark.type.name === "bold")) {
+        bold.push(node.text!);
+      }
+    });
+    return bold;
+  }
+
+  it.each(["src/__test__.tsx", "src/__tests__/a.ts", "pkg/__init__.py", "a/**b**/c"])(
+    "keeps %s literal after @ so file search can match it",
+    (path) => {
+      const doc = paste("Open @", path);
+      expect(boldText(doc)).toEqual([]);
+      expect(serializeEditorDoc(doc).value).toBe(`Open @${path}`);
+    },
+  );
+
+  it("still styles the text after the path", () => {
+    const doc = paste("Open @", "src/__test__.tsx and **this**\n- [ ] then __that__");
+    expect(boldText(doc)).toEqual(["this", "that"]);
+    expect(doc.lastChild!.type.name).toBe("taskList");
+    expect(serializeEditorDoc(doc).value).toBe(
+      "Open @src/__test__.tsx and **this**\n- [ ] then **that**",
+    );
+  });
+
+  it("keeps the rest of the path's line on that line", () => {
+    const doc = paste("Open @", "src/a.ts - not a list item");
+    expect(doc.childCount).toBe(1);
+    expect(serializeEditorDoc(doc).value).toBe("Open @src/a.ts - not a list item");
+  });
+
+  it("parses markdown when the paste does not continue a path query", () => {
+    expect(boldText(paste("Open ", "src/__test__.tsx"))).toEqual(["test"]);
+    expect(boldText(paste("Open @a ", "__b__"))).toEqual(["b"]);
+    expect(boldText(paste("Open @", " __b__"))).toEqual(["b"]);
+  });
+
+  it("keeps a path literal after a partly styled query", () => {
+    const doc = paste("Open @**src/**", "__test__.tsx");
+    expect(boldText(doc)).toEqual(["src/"]);
+    expect(serializeEditorDoc(doc).value).toBe("Open @**src/**__test__.tsx");
+  });
+
+  it("parses markdown pasted right after a mention chip", () => {
+    const withSpace = ProseMirrorNode.fromJSON(
+      schema,
+      buildDocJson("Open @README.md ", skillLabelFor),
+    );
+    const paragraph = withSpace.firstChild!;
+    expect(paragraph.lastChild!.text).toBe(" ");
+    const chipLast = schema.node("doc", null, [
+      paragraph.copy(paragraph.content.cut(0, paragraph.content.size - 1)),
+    ]);
+    expect(chipLast.firstChild!.lastChild!.type.name).toBe("composer-mention");
+    expect(boldText(paste(chipLast, "__b__"))).toEqual(["b"]);
+  });
+});
+
 describe("caret stops at styled edges", () => {
   function stateAt(value: string, pmPos: number) {
     const doc = ProseMirrorNode.fromJSON(

apps/web/src/composer-rich-text-doc.ts

@@ -534,10 +534,15 @@ function textJsonForSpan(text: string, marks: RichTextMark[]): Record<string, un
   return json;
 }
 
+/**
+ * Document content for a prompt. `literalLength` keeps that many leading
+ * characters as plain text, for a paste that continues a path query: markers
+ * inside a path such as `src/__init__.py` must reach file search unstyled.
+ */
 export function buildTiptapContent(
   value: string,
   skillLabelFor: (name: string) => SkillMeta,
-  options?: { styling?: boolean; blocks?: boolean; literalText?: boolean },
+  options?: { styling?: boolean; blocks?: boolean; literalText?: boolean; literalLength?: number },
 ): Record<string, unknown>[] {
   // Editor answers are verbatim text, including Markdown and context-token sources.
   if (options?.literalText) {
@@ -560,7 +565,8 @@ export function buildTiptapContent(
   // Code fences hold no chips, so their lines put the original source back in
   // place of the sentinel rather than building an atom for it.
   const atomSources: string[] = [];
-  const text = splitPromptIntoComposerSegments(value)
+  const literal = value.slice(0, options?.literalLength ?? 0);
+  const text = splitPromptIntoComposerSegments(value.slice(literal.length))
     .map((segment) => {
       if (segment.type === "text") return segment.text;
       atoms.push(atomJsonForSegment(segment, skillLabelFor));
@@ -608,6 +614,14 @@ export function buildTiptapContent(
 
   for (let index = 0; index < sourceLines.length; index += 1) {
     const line = sourceLines[index]!;
+    // The rest of the literal's line continues the text before the caret, so
+    // it cannot open a block.
+    if (index === 0 && literal) {
+      entries.push({
+        line: { list: null, inline: [textJsonForSpan(literal, []), ...buildInline(line)] },
+      });
+      continue;
+    }
     const opening = blockSyntax ? parseOpeningFence(line) : null;
     if (!opening) {
       // A thematic break outranks a list: `- - -` and `* * *` are rules, and