Diff Review · Stealth UI

Accept or reject an agent's edits hunk by hunk; decided hunks fold into a tick.

AI agents@base-ui/reactmotion@number-flow/reactsugar-high

01Preview

Fix the session refresh race

3 files·0 of 4 reviewed

Lines 14–23export async function refreshSession(token: string) {

const res = await fetch("/api/session/refresh", {

method: "POST",

headers: { authorization: `Bearer ${token}` },

});

if (!res.ok) return null;

if (res.status === 401) return null;

if (!res.ok) {

throw new SessionError("Couldn't refresh the session", res.status);

}

return (await res.json()) as Session;

}

Lines 44–51export function useSession() {

const [session, setSession] = useState<Session | null>(null);

// One refresh in flight at a time; later callers wait for the same promise.

const pending = useRef<Promise<Session | null> | null>(null);

useEffect(() => {

refreshSession(token).then(setSession);

pending.current ??= refreshSession(token).finally(() => (pending.current = null));

pending.current.then(setSession);

}, [token]);

02Install

Copy the source into your project. It becomes yours: no package to update, no wrapper between you and the markup. It needs:

npm install @base-ui/react motion @number-flow/react sugar-high

03Usage

import { DiffReview, parsePatch } from "@/components/ui/diff-review";

const files = parsePatch(await run("git diff"));

<DiffReview
  files={files}
  title="Fix the session refresh race"
  onComplete={(decisions) => applyAccepted(files, decisions)}
/>

04Source

758 lines

"use client";
import { Tabs } from "@base-ui/react/tabs";
import NumberFlow from "@number-flow/react";
import { AnimatePresence, motion, useReducedMotion } from "motion/react";
import { useEffect, useId, useMemo, useRef, useState } from "react";
import { highlight } from "sugar-high";
import { cn } from "@/lib/cn";
import { ArrowRight, Undo } from "@/lib/icons";
import { ease, spring } from "@/lib/motion";
import { useControllableState } from "@/lib/use-controllable-state";

/* -------------------------------------------------------------------------------------------------
 * Data
 * -----------------------------------------------------------------------------------------------*/

/** One hunk of a unified diff. Lines keep their prefix: "+" added, "-" removed, " " unchanged. */
export type DiffHunk = {
  /** Stable id. Falls back to the hunk's index in its file. */
  id?: string;
  oldStart: number;
  newStart: number;
  /** The text after the second @@, usually the enclosing function. */
  section?: string;
  lines: string[];
};

export type DiffFile = {
  path: string;
  status?: "modified" | "added" | "deleted" | "renamed";
  hunks: DiffHunk[];
};

export type HunkDecision = "accepted" | "rejected";
/** Decisions by hunk key (see `hunkKey`). A hunk that isn't in the record is still pending. */
export type DiffDecisions = Record<string, HunkDecision>;

export const hunkKey = (file: DiffFile, hunk: DiffHunk, index: number) => `${file.path}#${hunk.id ?? index}`;

const HEADER = /^@@ -(\d+)(?:,(\d+))? \+(\d+)(?:,(\d+))? @@ ?(.*)$/;
const stripPath = (p: string) => p.replace(/\t.*$/, "").replace(/^[ab]\//, "");

/** Turns `git diff` output (one or many files) into the shape DiffReview takes. */
export function parsePatch(patch: string): DiffFile[] {
  const files: DiffFile[] = [];
  let file: DiffFile | null = null;
  let hunk: DiffHunk | null = null;
  let oldLeft = 0;
  let newLeft = 0;
  const start = (path = "") => {
    file = { path, status: "modified", hunks: [] };
    files.push(file);
    hunk = null;
    return file;
  };

  for (const raw of patch.split(/\r?\n/)) {
    // Inside a hunk, the header's counts say where it ends, so a removed line
    // that happens to start with "--" is never mistaken for a file header.
    // A line that can't belong to a hunk ends it early, so a header with wrong counts can't swallow the next file.
    if (hunk && (oldLeft > 0 || newLeft > 0) && /^[+\- \\]|^$/.test(raw)) {
      if (raw.startsWith("\\")) continue;
      const sign = raw[0];
      if (sign !== "+") oldLeft--;
      if (sign !== "-") newLeft--;
      (hunk as DiffHunk).lines.push(sign === "+" || sign === "-" ? raw : ` ${raw.slice(1)}`);
      continue;
    }
    const h = HEADER.exec(raw);
    if (h) {
      const f: DiffFile = file ?? start("untitled");
      hunk = { oldStart: +h[1], newStart: +h[3], section: h[5] || undefined, lines: [] };
      oldLeft = h[2] === undefined ? 1 : +h[2];
      newLeft = h[4] === undefined ? 1 : +h[4];
      f.hunks.push(hunk);
    } else if (raw.startsWith("diff --git ")) {
      start(/ b\/(.+)$/.exec(raw)?.[1] ?? raw.slice(11));
    } else if (raw.startsWith("--- ")) {
      const current = file as DiffFile | null;
      const f: DiffFile = !current || current.hunks.length ? start() : current;
      if (raw.slice(4).startsWith("/dev/null")) f.status = "added";
      else if (!f.path) f.path = stripPath(raw.slice(4));
    } else if (raw.startsWith("+++ ") && file) {
      const f: DiffFile = file;
      if (raw.slice(4).startsWith("/dev/null")) f.status = "deleted";
      else f.path = stripPath(raw.slice(4));
    } else if (file && raw.startsWith("new file mode")) (file as DiffFile).status = "added";
    else if (file && raw.startsWith("deleted file mode")) (file as DiffFile).status = "deleted";
    else if (file && raw.startsWith("rename to ")) Object.assign(file as DiffFile, { status: "renamed", path: raw.slice(10) });
  }
  return files.filter((f) => f.hunks.length);
}

type Row = { sign: "+" | "-" | " "; html: string; old?: number; new?: number };
type HunkModel = { key: string; hunk: DiffHunk; rows: Row[]; adds: number; dels: number; from: number; to: number };

function model(file: DiffFile): HunkModel[] {
  return file.hunks.map((hunk, i) => {
    let o = hunk.oldStart;
    let n = hunk.newStart;
    let adds = 0;
    let dels = 0;
    const rows = hunk.lines.map((line): Row => {
      const sign = line[0] === "+" || line[0] === "-" ? line[0] : " ";
      // Highlighted one line at a time: good enough for review, and cheap.
      const html = highlight(line.slice(1) || " ");
      if (sign === "+") {
        adds++;
        return { sign, html, new: n++ };
      }
      if (sign === "-") {
        dels++;
        return { sign, html, old: o++ };
      }
      return { sign, html, old: o++, new: n++ };
    });
    const pureDelete = n === hunk.newStart;
    const from = pureDelete ? hunk.oldStart : hunk.newStart;
    const to = Math.max(from, (pureDelete ? o : n) - 1);
    return { key: hunkKey(file, hunk, i), hunk, rows, adds, dels, from, to };
  });
}

const tally = (hunks: HunkModel[], d: DiffDecisions) => {
  let decided = 0;
  let accepted = 0;
  for (const h of hunks) {
    if (d[h.key]) decided++;
    if (d[h.key] === "accepted") accepted++;
  }
  return { decided, accepted, rejected: decided - accepted, total: hunks.length };
};

/* -------------------------------------------------------------------------------------------------
 * DiffReview
 * -----------------------------------------------------------------------------------------------*/

export type DiffReviewProps = Omit<React.ComponentProps<"section">, "defaultValue" | "onChange"> & {
  files: DiffFile[];
  /** Decisions by hunk key. Controlled. */
  value?: DiffDecisions;
  defaultValue?: DiffDecisions;
  onValueChange?: (value: DiffDecisions) => void;
  /** Called once each time the last pending hunk is decided. */
  onComplete?: (value: DiffDecisions) => void;
  title?: string;
  /** The file shown first. Defaults to the first file with pending changes. */
  defaultFile?: string;
  /** Show the changes but block decisions, e.g. while the agent is still writing them. */
  disabled?: boolean;
};

type Focus = { key: string; part: "accept" | "undo" } | null;

// Diff tokens in four foreground steps: structure without a rainbow.
const tokens = {
  "--sh-keyword": "var(--fg)",
  "--sh-class": "var(--fg)",
  "--sh-entity": "var(--fg)",
  "--sh-identifier": "var(--fg)",
  "--sh-property": "var(--fg-2)",
  "--sh-string": "var(--fg-2)",
  "--sh-jsxliterals": "var(--fg-2)",
  "--sh-sign": "var(--fg-3)",
  "--sh-comment": "var(--fg-3)",
} as React.CSSProperties;

export function DiffReview({
  files,
  value,
  defaultValue,
  onValueChange,
  onComplete,
  title = "Proposed changes",
  defaultFile,
  disabled = false,
  className,
  style,
  ...rest
}: DiffReviewProps) {
  const reduce = !!useReducedMotion();
  const id = useId();
  const [decisions, setDecisions] = useControllableState<DiffDecisions>({ value, defaultValue: defaultValue ?? {}, onChange: onValueChange });
  const models = useMemo(() => files.map((f) => ({ file: f, hunks: model(f) })), [files]);
  const all = useMemo(() => models.flatMap((m) => m.hunks), [models]);
  const totals = tally(all, decisions);
  const done = totals.total > 0 && totals.decided === totals.total;

  // Chosen once: the requested file, else the first with something left to review.
  // Finishing a file never switches the view on its own; Next file does.
  const [picked, setPicked] = useState<string | undefined>(() => defaultFile ?? models.find((m) => m.hunks.some((h) => !decisions[h.key]))?.file.path);
  const active = models.some((m) => m.file.path === picked) ? picked! : models[0]?.file.path;

  const buttons = useRef(new Map<string, HTMLButtonElement>());
  const focusNext = useRef<Focus>(null);
  const [announcement, setAnnouncement] = useState("");

  // Focus moves after the render that mounted its target (an Undo, or the next Accept).
  useEffect(() => {
    const f = focusNext.current;
    if (!f) return;
    focusNext.current = null;
    buttons.current.get(`${f.part}:${f.key}`)?.focus({ preventScroll: false });
  });

  const commit = (next: DiffDecisions, message: string) => {
    setDecisions(next);
    setAnnouncement(message);
    const t = tally(all, next);
    if (t.total && t.decided === t.total && totals.decided !== totals.total) onComplete?.(next);
  };

  const decide = (fileIndex: number, h: HunkModel, decision: HunkDecision | null, viaKeyboard: boolean) => {
    if (disabled) return;
    const { file, hunks } = models[fileIndex];
    const next = { ...decisions };
    if (decision) next[h.key] = decision;
    else delete next[h.key];
    const n = hunks.indexOf(h) + 1;
    commit(next, decision ? `${decision === "accepted" ? "Accepted" : "Rejected"} change ${n} in ${basename(file.path)}` : `Change ${n} in ${basename(file.path)} is pending again`);

    if (!decision) {
      focusNext.current = { key: h.key, part: "accept" };
      return;
    }
    // Keep a keyboard reviewer moving: on to the next pending hunk in this file,
    // or onto this hunk's Undo when the file is finished. Pointers stay put.
    if (!viaKeyboard) return;
    const i = hunks.indexOf(h);
    const after = [...hunks.slice(i + 1), ...hunks.slice(0, i)].find((x) => !next[x.key]);
    focusNext.current = { key: (after ?? h).key, part: after ? "accept" : "undo" };
  };

  const acceptAll = () => {
    if (disabled || done) return;
    const next = { ...decisions };
    let count = 0;
    for (const h of all) {
      if (next[h.key]) continue;
      next[h.key] = "accepted";
      count++;
    }
    commit(next, `Accepted ${count} remaining ${count === 1 ? "change" : "changes"}`);
  };

  const openFile = (path: string) => {
    setPicked(path);
    const m = models.find((x) => x.file.path === path);
    const h = m?.hunks.find((x) => !decisions[x.key]);
    if (h) focusNext.current = { key: h.key, part: "accept" };
  };

  if (!files.length)
    return (
      <section aria-labelledby={`${id}-t`} className={cn("rounded-xl border border-line bg-raised px-4 py-8 text-center", className)} style={style} {...rest}>
        <h3 id={`${id}-t`} className="text-[13px] font-medium tracking-[-0.01em] text-fg">No changes to review</h3>
        <p className="mt-1 text-[12px] text-fg-3">When the agent proposes edits, they appear here file by file.</p>
      </section>
    );

  const fileCount = `${files.length} ${files.length === 1 ? "file" : "files"}`;

  return (
    <section
      aria-labelledby={`${id}-t`}
      data-state={done ? "done" : "pending"}
      data-disabled={disabled ? "" : undefined}
      className={cn("flex min-h-0 flex-col overflow-hidden rounded-xl border border-line-2 bg-raised shadow-[var(--shadow)]", className)}
      style={{ ...tokens, ...style }}
      {...rest}
    >
      <header className="relative flex items-center gap-3 border-b border-line py-2.5 pl-3.5 pr-2.5">
        <div className="min-w-0 flex-1">
          <h3 id={`${id}-t`} className="text-balance text-[13px] font-medium tracking-[-0.01em] text-fg">{title}</h3>
          <p className="tabular mt-px truncate text-[12px] text-fg-3">
            {fileCount}
            <span className="px-1.5 text-fg-4">·</span>
            <NumberFlow value={totals.decided} className="text-fg-2" /> of {totals.total} reviewed
          </p>
        </div>
        <AcceptAll done={done} pending={totals.total - totals.decided} disabled={disabled} reduce={reduce} onPress={acceptAll} />
        {/* Review progress along the header's edge. The text above says the same thing to a screen reader. */}
        <span aria-hidden className="absolute inset-x-0 -bottom-px h-px overflow-hidden">
          <span
            className="block h-full origin-left bg-fg-2 transition-transform duration-500 ease-out-expo motion-reduce:transition-none"
            style={{ transform: `scaleX(${totals.total ? totals.decided / totals.total : 0})` }}
          />
        </span>
      </header>

      <Tabs.Root orientation="vertical" value={active} onValueChange={(v) => setPicked(v as string)} className="flex min-h-0 flex-1 flex-col">
        <Tabs.List activateOnFocus aria-label="Changed files" className="relative flex shrink-0 flex-col border-b border-line p-1">
          <Tabs.Indicator className="absolute left-1 right-1 top-0 h-(--active-tab-height) translate-y-(--active-tab-top) rounded-md bg-fg/[0.06] transition-[translate,height] duration-220 ease-in-out-quart motion-reduce:transition-none" />
          {models.map(({ file, hunks }) => (
            <FileTab key={file.path} file={file} hunks={hunks} decisions={decisions} reduce={reduce} />
          ))}
        </Tabs.List>

        {models.map(({ file, hunks }, fi) => {
          const t = tally(hunks, decisions);
          const nextFile = models.find((m, i) => i !== fi && m.hunks.some((h) => !decisions[h.key]))?.file.path;
          return (
            <Tabs.Panel
              key={file.path}
              value={file.path}
              aria-label={`Changes in ${file.path}`}
              className="flex min-h-0 flex-1 flex-col gap-2 overflow-y-auto overscroll-contain p-2 outline-none focus-visible:outline-solid focus-visible:outline-1 focus-visible:-outline-offset-1 focus-visible:outline-fg-3"
            >
              {hunks.map((h, hi) => (
                <Hunk
                  key={h.key}
                  model={h}
                  index={hi}
                  count={hunks.length}
                  decision={decisions[h.key]}
                  disabled={disabled}
                  reduce={reduce}
                  register={(part, el) => {
                    const k = `${part}:${h.key}`;
                    if (el) buttons.current.set(k, el);
                    else buttons.current.delete(k);
                  }}
                  onDecide={(d, viaKeyboard) => decide(fi, h, d, viaKeyboard)}
                />
              ))}
              <AnimatePresence initial={false}>
                {t.decided === t.total && (
                  <motion.div
                    key="done"
                    initial={reduce ? { opacity: 0 } : { opacity: 0, y: 4 }}
                    animate={{ opacity: 1, y: 0 }}
                    exit={{ opacity: 0, transition: { duration: 0.12 } }}
                    transition={{ duration: 0.24, ease: ease.out, delay: reduce ? 0 : 0.12 }}
                    className="flex min-h-9 flex-wrap items-center gap-x-3 gap-y-1 px-1.5 text-[12px] text-fg-3"
                  >
                    <span className="min-w-0 flex-1">
                      {done ? `Review complete: ${outcome(totals)}` : `${basename(file.path)} reviewed: ${outcome(t)}`}
                    </span>
                    {nextFile && (
                      <button
                        type="button"
                        onClick={() => openFile(nextFile)}
                        className={cn(ghost, "group/next -mr-1 h-7 gap-1.5 px-2 text-[12px] text-fg-2")}
                      >
                        Next file
                        <ArrowRight size={14} className="transition-transform duration-150 ease-out group-hover/next:translate-x-0.5" />
                      </button>
                    )}
                  </motion.div>
                )}
              </AnimatePresence>
            </Tabs.Panel>
          );
        })}
      </Tabs.Root>

      <footer aria-hidden className="hidden shrink-0 items-center gap-3 border-t border-line px-3.5 py-2 font-mono text-2xs text-fg-4 pointer-fine:flex">
        <span className="whitespace-nowrap"><Kbd>A</Kbd>accept</span>
        <span className="whitespace-nowrap"><Kbd>R</Kbd>reject</span>
        <span className="whitespace-nowrap"><Kbd>U</Kbd>undo</span>
        <span className="ml-auto hidden truncate min-[480px]:block">in the focused change</span>
      </footer>

      <span role="status" aria-live="polite" className="sr-only">{announcement}</span>
    </section>
  );
}

/* -------------------------------------------------------------------------------------------------
 * Parts
 * -----------------------------------------------------------------------------------------------*/

const focusRing = "outline-none focus-visible:outline-solid focus-visible:outline-1 focus-visible:outline-offset-2 focus-visible:outline-fg-3";
const pressable = cn(
  focusRing,
  "relative inline-flex shrink-0 select-none items-center justify-center rounded-md font-medium",
  "transition-[background-color,border-color,color,scale] duration-150 ease-out active:scale-[0.96] active:duration-75",
  "disabled:pointer-events-none disabled:opacity-50",
  // 28px to draw, 44px to touch.
  "before:absolute before:-inset-x-1 before:-inset-y-2 before:content-[''] pointer-fine:before:hidden",
);
const ghost = cn(pressable, "text-fg-2 hover:bg-hover hover:text-fg");

function Kbd({ children }: { children: React.ReactNode }) {
  return <kbd className="mr-1 inline-grid h-4 min-w-4 place-items-center rounded border border-line-2 bg-frame px-1 text-[10px] text-fg-3">{children}</kbd>;
}

const basename = (p: string) => p.slice(p.lastIndexOf("/") + 1);
const outcome = ({ accepted, rejected }: { accepted: number; rejected: number }) =>
  [accepted && `${accepted} accepted`, rejected && `${rejected} rejected`].filter(Boolean).join(", ");

function AcceptAll({ done, pending, disabled, reduce, onPress }: { done: boolean; pending: number; disabled: boolean; reduce: boolean; onPress: () => void }) {
  const labels = ["Accept all", "All reviewed"];
  return (
    <button
      type="button"
      // Stays focusable once everything is reviewed so focus isn't dropped on the page.
      aria-disabled={done || undefined}
      disabled={disabled}
      data-state={done ? "done" : "pending"}
      aria-label={done ? "All changes reviewed" : `Accept all ${pending} remaining ${pending === 1 ? "change" : "changes"}`}
      onClick={onPress}
      className={cn(
        pressable,
        "h-7 gap-1.5 rounded-md px-2.5 text-[12px]",
        done
          ? "cursor-default border border-line-2 bg-transparent text-fg-2 active:scale-100"
          : "border border-transparent bg-fg text-frame hover:bg-fg/90",
      )}
    >
      <span className="relative grid size-3.5 place-items-center">
        <AnimatePresence initial={false}>
          {done && (
            <motion.svg
              key="tick"
              width={14}
              height={14}
              viewBox="0 0 16 16"
              fill="none"
              stroke="currentColor"
              strokeWidth={1.6}
              strokeLinecap="round"
              strokeLinejoin="round"
              aria-hidden
              className="absolute"
              initial={reduce ? { opacity: 0 } : { opacity: 0, scale: 0.6 }}
              animate={{ opacity: 1, scale: 1 }}
              exit={{ opacity: 0, transition: { duration: 0.1 } }}
              transition={reduce ? { duration: 0.15 } : spring.pop}
            >
              <motion.path d="M3.5 8.5 6.5 11.5 12.5 4.5" initial={reduce ? false : { pathLength: 0 }} animate={{ pathLength: 1 }} transition={{ duration: 0.32, ease: ease.out, delay: 0.06 }} />
            </motion.svg>
          )}
          {!done && (
            <motion.svg
              key="all"
              width={14}
              height={14}
              viewBox="0 0 16 16"
              fill="none"
              stroke="currentColor"
              strokeWidth={1.5}
              strokeLinecap="round"
              strokeLinejoin="round"
              aria-hidden
              className="absolute"
              initial={reduce ? { opacity: 0 } : { opacity: 0, scale: 0.6 }}
              animate={{ opacity: 1, scale: 1 }}
              exit={{ opacity: 0, scale: reduce ? 1 : 0.6, transition: { duration: 0.1 } }}
              transition={reduce ? { duration: 0.15 } : spring.pop}
            >
              <path d="M1.75 8.25 4.5 11 10 4.75M8 10.25l.75.75 5.5-6.25" />
            </motion.svg>
          )}
        </AnimatePresence>
      </span>
      {/* Both labels share one grid cell, so the button keeps its width when it flips. */}
      <span className="grid text-left">
        {labels.map((l) => (
          <span key={l} aria-hidden className="invisible col-start-1 row-start-1">{l}</span>
        ))}
        <AnimatePresence initial={false}>
          <motion.span
            key={done ? "done" : "todo"}
            className="col-start-1 row-start-1"
            initial={reduce ? { opacity: 0 } : { opacity: 0, y: 6, filter: "blur(2px)" }}
            animate={{ opacity: 1, y: 0, filter: "blur(0px)" }}
            exit={reduce ? { opacity: 0 } : { opacity: 0, y: -6, filter: "blur(2px)" }}
            transition={{ duration: reduce ? 0.15 : 0.22, ease: ease.out }}
          >
            {done ? labels[1] : labels[0]}
          </motion.span>
        </AnimatePresence>
      </span>
    </button>
  );
}

function FileTab({ file, hunks, decisions, reduce }: { file: DiffFile; hunks: HunkModel[]; decisions: DiffDecisions; reduce: boolean }) {
  const t = tally(hunks, decisions);
  const adds = hunks.reduce((s, h) => s + h.adds, 0);
  const dels = hunks.reduce((s, h) => s + h.dels, 0);
  const slash = file.path.lastIndexOf("/");
  const dir = slash >= 0 ? file.path.slice(0, slash + 1) : "";
  const name = file.path.slice(slash + 1);
  const spoken = t.decided === t.total ? "reviewed" : `${t.decided} of ${t.total} reviewed`;

  return (
    <Tabs.Tab
      value={file.path}
      aria-label={`${file.path}, ${adds} added, ${dels} removed, ${spoken}`}
      className={cn(
        "group/tab relative z-1 flex h-8 min-w-0 items-center gap-2 rounded-md px-2 text-left text-[12.5px] text-fg-2",
        "outline-none transition-[color,scale] duration-150 ease-out hover:text-fg active:scale-[0.99] data-active:text-fg",
        "focus-visible:outline-solid focus-visible:outline-1 focus-visible:-outline-offset-1 focus-visible:outline-fg-3",
      )}
    >
      <FileProgress decided={t.decided} total={t.total} rejectedAll={t.rejected === t.total} reduce={reduce} />
      <span className="flex min-w-0 flex-1 items-baseline font-mono text-[12px]">
        <span className="min-w-0 truncate text-fg-4">{dir}</span>
        <span className="shrink-0">{name}</span>
        {file.status && file.status !== "modified" && (
          <span className="ml-2 shrink-0 rounded-sm border border-line-2 px-1 text-[10px] leading-3.5 text-fg-3">
            {file.status === "added" ? "new" : file.status}
          </span>
        )}
      </span>
      <span aria-hidden className="tabular flex shrink-0 gap-1.5 font-mono text-[11px]">
        {adds > 0 && <span className="text-success">+{adds}</span>}
        {dels > 0 && <span className="text-danger">−{dels}</span>}
      </span>
    </Tabs.Tab>
  );
}

/** A ring that fills as hunks are decided, then turns into a tick (or a cross when all were rejected). */
function FileProgress({ decided, total, rejectedAll, reduce }: { decided: number; total: number; rejectedAll: boolean; reduce: boolean }) {
  const complete = decided === total;
  const c = 2 * Math.PI * 5.25;
  return (
    <span aria-hidden className="relative grid size-4 shrink-0 place-items-center">
      <AnimatePresence initial={false} mode="popLayout">
        {complete ? (
          <motion.svg
            key={rejectedAll ? "x" : "tick"}
            width={16}
            height={16}
            viewBox="0 0 16 16"
            fill="none"
            stroke="currentColor"
            strokeWidth={1.5}
            strokeLinecap="round"
            strokeLinejoin="round"
            className={rejectedAll ? "text-fg-3" : "text-success"}
            initial={reduce ? { opacity: 0 } : { opacity: 0, scale: 0.5 }}
            animate={{ opacity: 1, scale: 1 }}
            exit={{ opacity: 0, transition: { duration: 0.1 } }}
            transition={reduce ? { duration: 0.15 } : spring.pop}
          >
            {rejectedAll ? (
              <path d="m5 5 6 6M11 5l-6 6" />
            ) : (
              <motion.path d="M3.5 8.5 6.5 11.5 12.5 4.5" initial={reduce ? false : { pathLength: 0 }} animate={{ pathLength: 1 }} transition={{ duration: 0.3, ease: ease.out, delay: 0.05 }} />
            )}
          </motion.svg>
        ) : (
          <motion.svg key="ring" width={16} height={16} viewBox="0 0 16 16" fill="none" className="-rotate-90" exit={{ opacity: 0, scale: reduce ? 1 : 0.6, transition: { duration: 0.12 } }}>
            <circle cx="8" cy="8" r="5.25" stroke="var(--fg-4)" strokeOpacity={0.6} strokeWidth={1.5} />
            <circle
              cx="8"
              cy="8"
              r="5.25"
              stroke="var(--fg-2)"
              strokeWidth={1.5}
              strokeLinecap="round"
              strokeDasharray={c}
              strokeDashoffset={c * (1 - decided / total)}
              className="transition-[stroke-dashoffset] duration-300 ease-out-expo motion-reduce:transition-none"
              opacity={decided ? 1 : 0}
            />
          </motion.svg>
        )}
      </AnimatePresence>
    </span>
  );
}

function Hunk({
  model: h,
  index,
  count,
  decision,
  disabled,
  reduce,
  register,
  onDecide,
}: {
  model: HunkModel;
  index: number;
  count: number;
  decision?: HunkDecision;
  disabled: boolean;
  reduce: boolean;
  register: (part: "accept" | "undo", el: HTMLButtonElement | null) => void;
  onDecide: (decision: HunkDecision | null, viaKeyboard: boolean) => void;
}) {
  const decided = !!decision;
  const range = h.from === h.to ? `Line ${h.from}` : `Lines ${h.from}–${h.to}`;
  // detail is 0 for clicks that came from Enter or Space.
  const kb = (e: React.MouseEvent) => e.detail === 0;

  return (
    <div
      role="group"
      aria-label={`Change ${index + 1} of ${count}, ${range.toLowerCase()}${decision ? `, ${decision}` : ""}`}
      data-state={decision ?? "pending"}
      onKeyDown={(e) => {
        if (disabled || e.metaKey || e.ctrlKey || e.altKey || e.repeat) return;
        const k = e.key.toLowerCase();
        if (!decided && (k === "a" || k === "r")) {
          e.preventDefault();
          onDecide(k === "a" ? "accepted" : "rejected", true);
        } else if (decided && k === "u") {
          e.preventDefault();
          onDecide(null, true);
        }
      }}
      className={cn(
        "shrink-0 overflow-hidden rounded-lg border transition-[background-color,border-color] duration-200 ease-out",
        decided ? "border-line bg-frame/60" : "border-line-2 bg-frame",
      )}
    >
      <div className="flex h-10 items-center gap-2 pl-2.5 pr-1.5">
        <span aria-hidden className="relative grid size-4 shrink-0 place-items-center">
          <AnimatePresence initial={false} mode="popLayout">
            <motion.span
              key={decision ?? "pending"}
              className="grid place-items-center"
              initial={reduce ? { opacity: 0 } : { opacity: 0, scale: 0.5, filter: "blur(2px)" }}
              animate={{ opacity: 1, scale: 1, filter: "blur(0px)" }}
              exit={{ opacity: 0, transition: { duration: 0.1 } }}
              transition={reduce ? { duration: 0.15 } : spring.pop}
            >
              <HunkGlyph decision={decision} reduce={reduce} />
            </motion.span>
          </AnimatePresence>
        </span>

        <span className="flex min-w-0 flex-1 items-baseline gap-2 font-mono text-[11.5px]">
          <span className={cn("shrink-0 transition-colors duration-200", decided ? "text-fg-3" : "text-fg-2")}>
            {decision === "accepted" ? "Accepted" : decision === "rejected" ? "Rejected" : range}
          </span>
          {decided && <span className="shrink-0 text-fg-4">{range}</span>}
          {!decided && h.hunk.section && <span className="min-w-0 truncate text-fg-4">{h.hunk.section}</span>}
          <span aria-hidden className={cn("tabular ml-auto hidden shrink-0 gap-1.5 text-[11px] min-[420px]:flex", decision === "rejected" && "line-through decoration-fg-4")}>
            {h.adds > 0 && <span className={decided ? "text-fg-4" : "text-success"}>+{h.adds}</span>}
            {h.dels > 0 && <span className={decided ? "text-fg-4" : "text-danger"}>−{h.dels}</span>}
          </span>
        </span>

        {/* The actions swap in place; the row never changes height. */}
        <span className="relative flex shrink-0 items-center justify-end">
          <AnimatePresence initial={false} mode="popLayout">
            {decided ? (
              <motion.span
                key="undo"
                initial={reduce ? { opacity: 0 } : { opacity: 0, x: 6, filter: "blur(2px)" }}
                animate={{ opacity: 1, x: 0, filter: "blur(0px)" }}
                exit={reduce ? { opacity: 0 } : { opacity: 0, x: 6, filter: "blur(2px)", transition: { duration: 0.12 } }}
                transition={{ duration: 0.22, ease: ease.out, delay: reduce ? 0 : 0.08 }}
                className="flex"
              >
                <button
                  ref={(el) => register("undo", el)}
                  type="button"
                  disabled={disabled}
                  aria-keyshortcuts="u"
                  aria-label={`Undo ${decision === "accepted" ? "accept" : "reject"}, ${range.toLowerCase()}`}
                  onClick={(e) => onDecide(null, kb(e))}
                  className={cn(ghost, "group/undo h-7 gap-1.5 px-2 text-[12px]")}
                >
                  <Undo size={14} className="transition-transform duration-200 ease-out group-hover/undo:-rotate-12" />
                  Undo
                </button>
              </motion.span>
            ) : (
              <motion.span
                key="actions"
                initial={reduce ? { opacity: 0 } : { opacity: 0, x: -6, filter: "blur(2px)" }}
                animate={{ opacity: 1, x: 0, filter: "blur(0px)" }}
                exit={reduce ? { opacity: 0 } : { opacity: 0, scale: 0.96, filter: "blur(2px)", transition: { duration: 0.12 } }}
                transition={{ duration: 0.22, ease: ease.out }}
                className="flex gap-1"
              >
                <button
                  type="button"
                  disabled={disabled}
                  aria-keyshortcuts="r"
                  aria-label={`Reject, ${range.toLowerCase()}`}
                  onClick={(e) => onDecide("rejected", kb(e))}
                  className={cn(ghost, "h-7 px-2 text-[12px] hover:text-danger")}
                >
                  Reject
                </button>
                <button
                  ref={(el) => register("accept", el)}
                  type="button"
                  disabled={disabled}
                  aria-keyshortcuts="a"
                  aria-label={`Accept, ${range.toLowerCase()}`}
                  onClick={(e) => onDecide("accepted", kb(e))}
                  className={cn(pressable, "h-7 border border-line-2 bg-raised px-2.5 text-[12px] text-fg shadow-[var(--shadow)] hover:border-fg-4 hover:bg-hover")}
                >
                  Accept
                </button>
              </motion.span>
            )}
          </AnimatePresence>
        </span>
      </div>

      {/* Decided hunks fold away to their header; Undo unfolds them from the same place. */}
      <motion.div
        initial={false}
        animate={decided ? { height: 0, opacity: 0 } : { height: "auto", opacity: 1 }}
        transition={
          reduce
            ? { duration: 0.15 }
            : decided
              ? { height: { duration: 0.28, ease: ease.inOut, delay: 0.06 }, opacity: { duration: 0.16, ease: ease.out } }
              : { height: { duration: 0.3, ease: ease.out }, opacity: { duration: 0.2, ease: ease.out, delay: 0.06 } }
        }
        inert={decided}
        className="overflow-hidden"
      >
        <div className="overflow-x-auto overscroll-x-contain border-t border-line">
          <div className="w-max min-w-full py-1 font-mono text-[12px] leading-5">
            {h.rows.map((r, i) => (
              <div
                key={i}
                className={cn(
                  "flex whitespace-pre",
                  r.sign === "+" && "bg-success-soft",
                  r.sign === "-" && "bg-danger-soft",
                )}
              >
                <span aria-hidden className="tabular w-9 shrink-0 select-none pr-1.5 text-right text-fg-4">{r.old ?? ""}</span>
                <span aria-hidden className="tabular w-9 shrink-0 select-none pr-1.5 text-right text-fg-4">{r.new ?? ""}</span>
                <span aria-hidden className={cn("w-4 shrink-0 select-none text-center", r.sign === "+" ? "text-success" : r.sign === "-" ? "text-danger" : "text-fg-4")}>
                  {r.sign === "+" ? "+" : r.sign === "-" ? "−" : ""}
                </span>
                {r.sign !== " " && <span className="sr-only">{r.sign === "+" ? "Added: " : "Removed: "}</span>}
                <code className={cn("pr-4", r.sign === "-" && "opacity-80")} dangerouslySetInnerHTML={{ __html: r.html }} />
              </div>
            ))}
          </div>
        </div>
      </motion.div>
    </div>
  );
}

function HunkGlyph({ decision, reduce }: { decision?: HunkDecision; reduce: boolean }) {
  const draw = reduce ? {} : { initial: { pathLength: 0 }, animate: { pathLength: 1 } };
  if (decision === "accepted")
    return (
      <svg width={14} height={14} viewBox="0 0 16 16" fill="none" stroke="currentColor" strokeWidth={1.6} strokeLinecap="round" strokeLinejoin="round" className="text-success">
        <motion.path d="M3.5 8.5 6.5 11.5 12.5 4.5" {...draw} transition={{ duration: 0.32, ease: ease.out, delay: 0.05 }} />
      </svg>
    );
  if (decision === "rejected")
    return (
      <svg width={14} height={14} viewBox="0 0 16 16" fill="none" stroke="currentColor" strokeWidth={1.6} strokeLinecap="round" className="text-fg-3">
        <motion.path d="m4.5 4.5 7 7" {...draw} transition={{ duration: 0.2, ease: ease.out, delay: 0.04 }} />
        <motion.path d="m11.5 4.5-7 7" {...draw} transition={{ duration: 0.2, ease: ease.out, delay: 0.14 }} />
      </svg>
    );
  return <span className="size-1.5 rounded-full bg-fg-4" />;
}

05Props

DiffReview

Prop	Type	Default	Description
files*	DiffFile[]	—	Files with their hunks. Hunk lines keep their unified-diff prefix: "+", "-" or " ". An empty list renders the empty state.
value	Record<string, "accepted" \| "rejected">	—	Decisions keyed by hunkKey(file, hunk, index). A hunk missing from the record is pending.
defaultValue	Record<string, "accepted" \| "rejected">	{}	Uncontrolled starting decisions.
onValueChange	(value) => void	—	Called with the whole record after every accept, reject, undo or Accept all.
onComplete	(value) => void	—	Called when the last pending hunk is decided. Fires again if an Undo reopens one and it is decided again.
title	string	"Proposed changes"	Names the review; wraps rather than truncating.
defaultFile	string	—	Path of the file shown first. Defaults to the first file with pending hunks.
disabled	boolean	false	Shows the changes but blocks decisions, for while the agent is still writing.

parsePatch

Prop	Type	Default	Description
patch*	string	—	git diff output for one or many files. Returns DiffFile[], with new, deleted and renamed files marked.

hunkKey

Prop	Type	Default	Description
(file, hunk, index)	string	—	The key a hunk's decision is stored under: path#id, or path#index when the hunk has no id.

06Notes

Behavior

Accept all only fills pending hunks; anything already rejected stays rejected. Once nothing is pending it becomes All reviewed and stays focusable, so keyboard focus is never dropped.
Finishing a file never switches the view by itself. A summary row appears with Next file, which opens the next file that still has pending changes.
From the keyboard, deciding a hunk moves focus to the next pending hunk in the file, or to its own Undo when the file is done. Pointer decisions leave focus and scroll alone.
Long lines scroll sideways inside their hunk; paths truncate the directory and keep the file name. Zero counts are left out instead of showing −0.
The patch parser trusts each hunk header's line counts, and ends a hunk early at any line a hunk can't contain, so a bad count can't swallow the next file.

Motion

A decided hunk folds its body to its header: height over 280ms on the in-out curve after a 60ms beat, while the lines fade in 160ms. Undo unfolds it in 300ms ease-out.
The status glyph pops in on the pop spring and the tick draws in 320ms. The actions slide 6px and blur out as Undo slides in, inside a slot of fixed height.
Each file's ring fills over 300ms as its hunks are decided, then turns into a tick (or a cross when all were rejected). A hairline along the header tracks the whole review over 500ms.
The review count rolls with NumberFlow. Reduced motion keeps 150ms fades and drops the folds' travel, the draws, the blur and the rolling.

Accessibility

Files are a vertical tab list: arrow keys move between files and open them, and Tab goes into the file's changes.
Each hunk is a labelled group ("Change 2 of 3, lines 44–51") with A to accept, R to reject and U to undo while focus is inside it, listed in aria-keyshortcuts and in the footer on pointer devices.
Added and removed lines carry hidden Added and Removed prefixes, so the diff doesn't rely on color. Folded hunk bodies are inert.
A polite live region announces each decision ("Accepted change 1 in session.ts") and Accept all's count.