import assert from "node:assert";
import { describe, it } from "node:test";
import { Image } from "../src/components/image.js";
import {
deleteAllKittyImages,
deleteKittyImage,
detectCapabilities,
encodeKitty,
hyperlink,
isImageLine,
renderImage,
resetCapabilitiesCache,
setCapabilities,
setCellDimensions,
} from "../src/terminal-image.js";
const ENV_KEYS = [
"TERM",
"TERM_PROGRAM",
"COLORTERM",
"TMUX",
"KITTY_WINDOW_ID",
"GHOSTTY_RESOURCES_DIR",
"WEZTERM_PANE",
"ITERM_SESSION_ID",
"CMUX_WORKSPACE_ID",
] as const;
function withEnv(overrides: Record<string, string | undefined>, fn: () => void): void {
const saved: Record<string, string | undefined> = {};
for (const key of ENV_KEYS) {
saved[key] = process.env[key];
delete process.env[key];
}
try {
for (const [k, v] of Object.entries(overrides)) {
if (v === undefined) delete process.env[k];
else process.env[k] = v;
}
fn();
} finally {
for (const key of ENV_KEYS) {
if (saved[key] === undefined) delete process.env[key];
else process.env[key] = saved[key];
}
}
}
describe("isImageLine", () => {
describe("iTerm2 image protocol", () => {
it("should detect iTerm2 image escape sequence at start of line", () => {
const iterm2ImageLine = "\x1b]1337;File=size=100,100;inline=1:base64encodeddata==\x07";
assert.strictEqual(isImageLine(iterm2ImageLine), true);
});
it("should detect iTerm2 image escape sequence with text before it", () => {
const lineWithTextAndImage = "Some text \x1b]1337;File=size=100,100;inline=1:base64data==\x07 more text";
assert.strictEqual(isImageLine(lineWithTextAndImage), true);
});
it("should detect iTerm2 image escape sequence in middle of long line", () => {
const longLineWithImage =
"Text before image..." + "\x1b]1337;File=inline=1:verylongbase64data==" + "...text after";
assert.strictEqual(isImageLine(longLineWithImage), true);
});
it("should detect iTerm2 image escape sequence at end of line", () => {
const lineWithImageAtEnd = "Regular text ending with \x1b]1337;File=inline=1:base64data==\x07";
assert.strictEqual(isImageLine(lineWithImageAtEnd), true);
});
it("should detect minimal iTerm2 image escape sequence", () => {
const minimalImageLine = "\x1b]1337;File=:\x07";
assert.strictEqual(isImageLine(minimalImageLine), true);
});
});
describe("Kitty image protocol", () => {
it("should detect Kitty image escape sequence at start of line", () => {
const kittyImageLine = "\x1b_Ga=T,f=100,t=f,d=base64data...\x1b\\\x1b_Gm=i=1;\x1b\\";
assert.strictEqual(isImageLine(kittyImageLine), true);
});
it("should detect Kitty image escape sequence with text before it", () => {
const lineWithTextAndKittyImage = "Output: \x1b_Ga=T,f=100;data...\x1b\\\x1b_Gm=i=1;\x1b\\";
assert.strictEqual(isImageLine(lineWithTextAndKittyImage), true);
});
it("should detect Kitty image escape sequence with padding", () => {
const kittyWithPadding = " \x1b_Ga=T,f=100...\x1b\\\x1b_Gm=i=1;\x1b\\ ";
assert.strictEqual(isImageLine(kittyWithPadding), true);
});
});
describe("Bug regression tests", () => {
it("should detect image sequences in very long lines (304k+ chars)", () => {
const base64Char = "A".repeat(100); // 100 chars of base64-like data
const imageSequence = "\x1b]1337;File=size=800,600;inline=1:";
const longLine =
"Text prefix " +
imageSequence +
base64Char.repeat(3000) + // ~300,000 chars
" suffix";
assert.strictEqual(longLine.length > 300000, true);
assert.strictEqual(isImageLine(longLine), true);
});
it("should detect image sequences when terminal doesn't support images", () => {
const lineWithImage = "Read image file [image/jpeg]\x1b]1337;File=inline=1:base64data==\x07";
assert.strictEqual(isImageLine(lineWithImage), true);
});
it("should detect image sequences with ANSI codes before them", () => {
const lineWithAnsiAndImage = "\x1b[31mError output \x1b]1337;File=inline=1:image==\x07";
assert.strictEqual(isImageLine(lineWithAnsiAndImage), true);
});
it("should detect image sequences with ANSI codes after them", () => {
const lineWithImageAndAnsi = "\x1b_Ga=T,f=100:data...\x1b\\\x1b_Gm=i=1;\x1b\\\x1b[0m reset";
assert.strictEqual(isImageLine(lineWithImageAndAnsi), true);
});
});
describe("Negative cases - lines without images", () => {
it("should not detect images in plain text lines", () => {
const plainText = "This is just a regular text line without any escape sequences";
assert.strictEqual(isImageLine(plainText), false);
});
it("should not detect images in lines with only ANSI codes", () => {
const ansiText = "\x1b[31mRed text\x1b[0m and \x1b[32mgreen text\x1b[0m";
assert.strictEqual(isImageLine(ansiText), false);
});
it("should not detect images in lines with cursor movement codes", () => {
const cursorCodes = "\x1b[1A\x1b[2KLine cleared and moved up";
assert.strictEqual(isImageLine(cursorCodes), false);
});
it("should not detect images in lines with partial iTerm2 sequences", () => {
const partialSequence = "Some text with ]1337;File but missing ESC at start";
assert.strictEqual(isImageLine(partialSequence), false);
});
it("should not detect images in lines with partial Kitty sequences", () => {
const partialSequence = "Some text with _G but missing ESC at start";
assert.strictEqual(isImageLine(partialSequence), false);
});
it("should not detect images in empty lines", () => {
assert.strictEqual(isImageLine(""), false);
});
it("should not detect images in lines with newlines only", () => {
assert.strictEqual(isImageLine("\n"), false);
assert.strictEqual(isImageLine("\n\n"), false);
});
});
describe("Mixed content scenarios", () => {
it("should detect images when line has both Kitty and iTerm2 sequences", () => {
const mixedLine = "Kitty: \x1b_Ga=T...\x1b\\\x1b_Gm=i=1;\x1b\\ iTerm2: \x1b]1337;File=inline=1:data==\x07";
assert.strictEqual(isImageLine(mixedLine), true);
});
it("should detect image in line with multiple text and image segments", () => {
const complexLine = "Start \x1b]1337;File=img1==\x07 middle \x1b]1337;File=img2==\x07 end";
assert.strictEqual(isImageLine(complexLine), true);
});
it("should not falsely detect image in line with file path containing keywords", () => {
const filePathLine = "/path/to/File_1337_backup/image.jpg";
assert.strictEqual(isImageLine(filePathLine), false);
});
});
});
describe("detectCapabilities", () => {
it("defaults to hyperlinks: false for unknown terminals", () => {
withEnv({}, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, false);
assert.strictEqual(caps.images, null);
});
});
it("forces hyperlinks: false under tmux even if outer terminal supports OSC 8", () => {
withEnv({ TMUX: "/tmp/tmux-1000/default,1234,0", TERM_PROGRAM: "ghostty" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, false);
assert.strictEqual(caps.images, null);
});
});
it("forces hyperlinks: false when TERM starts with 'tmux'", () => {
withEnv({ TERM: "tmux-256color", TERM_PROGRAM: "iterm.app" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, false);
assert.strictEqual(caps.images, null);
});
});
it("forces hyperlinks: false when TERM starts with 'screen'", () => {
withEnv({ TERM: "screen-256color" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, false);
assert.strictEqual(caps.images, null);
});
});
it("enables hyperlinks for Ghostty", () => {
withEnv({ TERM_PROGRAM: "ghostty" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, true);
});
});
it("does not disable Ghostty images solely because cmux is present", () => {
withEnv({ TERM_PROGRAM: "ghostty", CMUX_WORKSPACE_ID: "workspace" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.images, "kitty");
assert.strictEqual(caps.hyperlinks, true);
});
});
it("enables hyperlinks for Kitty", () => {
withEnv({ KITTY_WINDOW_ID: "1" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, true);
});
});
it("enables hyperlinks for WezTerm", () => {
withEnv({ WEZTERM_PANE: "0" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, true);
});
});
it("enables hyperlinks for iTerm2", () => {
withEnv({ TERM_PROGRAM: "iterm.app" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, true);
});
});
it("enables hyperlinks for VSCode", () => {
withEnv({ TERM_PROGRAM: "vscode" }, () => {
const caps = detectCapabilities();
assert.strictEqual(caps.hyperlinks, true);
});
});
});
describe("Kitty image cursor movement", () => {
it("can request no terminal-side cursor movement", () => {
const sequence = encodeKitty("AAAA", { columns: 2, rows: 2, moveCursor: false });
assert.ok(sequence.startsWith("\x1b_Ga=T,f=100,q=2,C=1,c=2,r=2;"));
});
it("suppresses Kitty replies for delete commands", () => {
assert.strictEqual(deleteKittyImage(42), "\x1b_Ga=d,d=I,i=42,q=2\x1b\\");
assert.strictEqual(deleteAllKittyImages(), "\x1b_Ga=d,d=A,q=2\x1b\\");
});
it("preserves renderImage's default terminal-side cursor movement", () => {
setCapabilities({ images: "kitty", trueColor: true, hyperlinks: true });
setCellDimensions({ widthPx: 10, heightPx: 10 });
try {
const result = renderImage("AAAA", { widthPx: 20, heightPx: 20 }, { maxWidthCells: 2 });
assert.ok(result);
assert.ok(!result.sequence.includes(",C=1,"));
assert.strictEqual(result.rows, 2);
} finally {
resetCapabilitiesCache();
setCellDimensions({ widthPx: 9, heightPx: 18 });
}
});
it("can opt renderImage into no terminal-side cursor movement", () => {
setCapabilities({ images: "kitty", trueColor: true, hyperlinks: true });
setCellDimensions({ widthPx: 10, heightPx: 10 });
try {
const result = renderImage("AAAA", { widthPx: 20, heightPx: 20 }, { maxWidthCells: 2, moveCursor: false });
assert.ok(result);
assert.ok(result.sequence.includes(",C=1,"));
assert.strictEqual(result.rows, 2);
} finally {
resetCapabilitiesCache();
setCellDimensions({ widthPx: 9, heightPx: 18 });
}
});
it("restores the cursor to the reserved image row after Kitty rendering", () => {
setCapabilities({ images: "kitty", trueColor: true, hyperlinks: true });
setCellDimensions({ widthPx: 10, heightPx: 10 });
try {
const image = new Image(
"AAAA",
"image/png",
{ fallbackColor: (value) => value },
{ maxWidthCells: 2 },
{ widthPx: 20, heightPx: 20 },
);
const lines = image.render(4);
const imageId = image.getImageId();
assert.strictEqual(typeof imageId, "number");
assert.deepStrictEqual(lines.slice(0, -1), [""]);
assert.ok(lines[1].startsWith("\x1b[1A\x1b_G"));
assert.ok(lines[1].includes(",C=1,"));
assert.ok(lines[1].includes(`,i=${imageId}`));
assert.ok(lines[1].endsWith("\x1b[1B"));
} finally {
resetCapabilitiesCache();
setCellDimensions({ widthPx: 9, heightPx: 18 });
}
});
it("keeps compact metadata and its prefix when terminal graphics are unavailable", () => {
setCapabilities({ images: null, trueColor: true, hyperlinks: true });
try {
const image = new Image(
"AAAA",
"image/png",
{ fallbackColor: (value) => value },
{ filename: "result.png", fallbackOnly: true, fallbackPrefix: " ╰─ " },
{ widthPx: 20, heightPx: 10 },
);
assert.deepStrictEqual(image.render(80), [" ╰─ [result.png · image/png · 20×10]"]);
} finally {
resetCapabilitiesCache();
}
});
});
describe("hyperlink", () => {
it("wraps text in OSC 8 open and close sequences", () => {
const result = hyperlink("click me", "https://example.com");
assert.strictEqual(result, "\x1b]8;;https://example.com\x1b\\click me\x1b]8;;\x1b\\");
});
it("preserves ANSI styling inside the hyperlink", () => {
const styled = "\x1b[4m\x1b[34mclick me\x1b[0m";
const result = hyperlink(styled, "https://example.com");
assert.ok(result.startsWith("\x1b]8;;https://example.com\x1b\\"));
assert.ok(result.includes(styled));
assert.ok(result.endsWith("\x1b]8;;\x1b\\"));
});
it("works with empty text", () => {
const result = hyperlink("", "https://example.com");
assert.strictEqual(result, "\x1b]8;;https://example.com\x1b\\\x1b]8;;\x1b\\");
});
it("works with file:// URIs", () => {
const result = hyperlink("README.md", "file:///home/user/README.md");
assert.ok(result.includes("file:///home/user/README.md"));
assert.ok(result.includes("README.md"));
});
});