paperclip/ui/src/lib/angle-bracket-markdown.test.ts

284 lines
11 KiB
TypeScript

import { describe, expect, it } from "vitest";
import {
escapeUnsupportedAngleBrackets,
unescapeAngleBracketEscapes,
} from "./angle-bracket-markdown";
describe("escapeUnsupportedAngleBrackets", () => {
it("leaves markdown without angle brackets untouched", () => {
expect(escapeUnsupportedAngleBrackets("")).toBe("");
expect(escapeUnsupportedAngleBrackets("plain prose")).toBe("plain prose");
});
it("escapes a placeholder written in prose", () => {
expect(escapeUnsupportedAngleBrackets("Rename <name> to the real name")).toBe(
"Rename \\<name> to the real name",
);
});
it("escapes closing tags, comments and processing instructions", () => {
expect(escapeUnsupportedAngleBrackets("a </close> b")).toBe("a \\</close> b");
expect(escapeUnsupportedAngleBrackets("a <!-- note --> b")).toBe("a \\<!-- note --> b");
expect(escapeUnsupportedAngleBrackets("a <?php b")).toBe("a \\<?php b");
});
it("escapes every eligible bracket on a line", () => {
expect(escapeUnsupportedAngleBrackets("<a> and <b>")).toBe("\\<a> and \\<b>");
});
it("leaves a bracket that cannot open HTML alone", () => {
expect(escapeUnsupportedAngleBrackets("Affected versions: <= v0.3.1")).toBe(
"Affected versions: <= v0.3.1",
);
expect(escapeUnsupportedAngleBrackets("2 < 3 and 4 > 1")).toBe("2 < 3 and 4 > 1");
expect(escapeUnsupportedAngleBrackets("a <1 b")).toBe("a <1 b");
expect(escapeUnsupportedAngleBrackets("trailing <")).toBe("trailing <");
});
it("escapes a bracket next to one that cannot open HTML", () => {
expect(escapeUnsupportedAngleBrackets("use <= or <name>")).toBe("use <= or \\<name>");
});
it("does not double-escape an already-escaped bracket", () => {
expect(escapeUnsupportedAngleBrackets("Rename \\<name> here")).toBe("Rename \\<name> here");
});
it("escapes a bracket that follows a literal backslash", () => {
// `\\` is an escaped backslash, so the `<` after it is still bare markup.
expect(escapeUnsupportedAngleBrackets("a \\\\<name> b")).toBe("a \\\\\\<name> b");
});
it("skips inline code spans", () => {
expect(escapeUnsupportedAngleBrackets("Use `<name>` here")).toBe("Use `<name>` here");
expect(escapeUnsupportedAngleBrackets("Use ``a <b> c`` here")).toBe("Use ``a <b> c`` here");
});
it("escapes outside a code span on the same line", () => {
expect(escapeUnsupportedAngleBrackets("`<a>` then <b>")).toBe("`<a>` then \\<b>");
});
it("treats an unmatched backtick as literal text, not a code span", () => {
// CommonMark only forms a code span from a matched pair of equal-length
// backtick runs, so the bracket after a lone backtick is still markup.
expect(escapeUnsupportedAngleBrackets("a ` b <name> c")).toBe("a ` b \\<name> c");
expect(escapeUnsupportedAngleBrackets("a ``b` c <name>")).toBe("a ``b` c \\<name>");
});
it("treats a backslash-escaped backtick as literal text", () => {
expect(escapeUnsupportedAngleBrackets("a \\`x` b <name>")).toBe("a \\`x` b \\<name>");
});
it("skips a code span that wraps across a soft line break", () => {
expect(escapeUnsupportedAngleBrackets("a `one\ntwo <x>` b <y>")).toBe(
"a `one\ntwo <x>` b \\<y>",
);
});
it("does not carry a code span across a blank line", () => {
// A blank line ends the paragraph, so the opening backtick never matches.
expect(escapeUnsupportedAngleBrackets("a `one <x>\n\ntwo` b <y>")).toBe(
"a `one \\<x>\n\ntwo` b \\<y>",
);
});
it("skips fenced code blocks", () => {
expect(escapeUnsupportedAngleBrackets("```\n<name>\n```\n<after>")).toBe(
"```\n<name>\n```\n\\<after>",
);
expect(escapeUnsupportedAngleBrackets("~~~ts\n<name>\n~~~")).toBe("~~~ts\n<name>\n~~~");
});
it("skips a fenced code block nested in a blockquote", () => {
expect(escapeUnsupportedAngleBrackets("> ```\n> <name>\n> ```\n<after>")).toBe(
"> ```\n> <name>\n> ```\n\\<after>",
);
});
it("skips a fenced code block nested in a list", () => {
expect(escapeUnsupportedAngleBrackets("- ```\n <name>\n ```\n<after>")).toBe(
"- ```\n <name>\n ```\n\\<after>",
);
});
it("does not close a fence on a shorter run of the same character", () => {
expect(escapeUnsupportedAngleBrackets("````\n<a>\n```\n<b>\n````\n<c>")).toBe(
"````\n<a>\n```\n<b>\n````\n\\<c>",
);
});
it("skips indented code blocks", () => {
expect(escapeUnsupportedAngleBrackets("intro\n\n <name>\n\nafter <x>")).toBe(
"intro\n\n <name>\n\nafter \\<x>",
);
expect(escapeUnsupportedAngleBrackets("\t<name>")).toBe("\t<name>");
});
it("escapes an indented lazy paragraph continuation", () => {
// Indented code cannot interrupt a paragraph, so this line is prose.
expect(escapeUnsupportedAngleBrackets("para\n more <name> here")).toBe(
"para\n more \\<name> here",
);
});
it("escapes prose inside a blockquote but skips quoted indented code", () => {
expect(escapeUnsupportedAngleBrackets("> Rename <name> here")).toBe(
"> Rename \\<name> here",
);
expect(escapeUnsupportedAngleBrackets(">\n> <name>")).toBe(">\n> <name>");
});
it("skips autolinks", () => {
expect(escapeUnsupportedAngleBrackets("See <https://example.com> for more")).toBe(
"See <https://example.com> for more",
);
expect(escapeUnsupportedAngleBrackets("Mail <a.b@example.com> now")).toBe(
"Mail <a.b@example.com> now",
);
});
it("escapes a tag that only looks like an autolink", () => {
expect(escapeUnsupportedAngleBrackets("<notascheme>")).toBe("\\<notascheme>");
});
it("skips pointed-bracket link destinations", () => {
expect(escapeUnsupportedAngleBrackets("[a](<my file.md>)")).toBe("[a](<my file.md>)");
expect(escapeUnsupportedAngleBrackets("![i](<f.png>)")).toBe("![i](<f.png>)");
});
it("still escapes prose around a pointed link destination", () => {
expect(escapeUnsupportedAngleBrackets("[a](<f.md>) then <name>")).toBe(
"[a](<f.md>) then \\<name>",
);
});
it("is idempotent", () => {
const inputs = [
"Rename <name> to the real name",
"Use `<name>` and <other>",
"a \\\\<name> b",
"```\n<name>\n```\n<after>",
"See <https://example.com> and <name>",
"[a](<f.md>) then <name>",
];
for (const input of inputs) {
const once = escapeUnsupportedAngleBrackets(input);
expect(escapeUnsupportedAngleBrackets(once)).toBe(once);
}
});
});
describe("unescapeAngleBracketEscapes", () => {
it("leaves markdown without escapes untouched", () => {
expect(unescapeAngleBracketEscapes("")).toBe("");
expect(unescapeAngleBracketEscapes("Rename <name> here")).toBe("Rename <name> here");
});
it("drops the backslash from an escaped html-like bracket", () => {
expect(unescapeAngleBracketEscapes("Rename \\<name> here")).toBe("Rename <name> here");
expect(unescapeAngleBracketEscapes("a \\</close> b")).toBe("a </close> b");
expect(unescapeAngleBracketEscapes("a \\<!-- note --> b")).toBe("a <!-- note --> b");
expect(unescapeAngleBracketEscapes("a \\<?php b")).toBe("a <?php b");
});
it("leaves an escape that does not hide an html construct alone", () => {
expect(unescapeAngleBracketEscapes("a \\<= b")).toBe("a \\<= b");
expect(unescapeAngleBracketEscapes("a \\<1 b")).toBe("a \\<1 b");
});
it("leaves other backslash escapes alone", () => {
expect(unescapeAngleBracketEscapes("a \\> b and \\* c and \\<name>")).toBe(
"a \\> b and \\* c and <name>",
);
});
it("keeps backslash parity", () => {
// `\\` is a literal backslash; the `<name>` after it is already bare.
expect(unescapeAngleBracketEscapes("a \\\\<name> b")).toBe("a \\\\<name> b");
// `\\` then `\<` is a literal backslash followed by an escaped bracket.
expect(unescapeAngleBracketEscapes("a \\\\\\<name> b")).toBe("a \\\\<name> b");
});
it("keeps an escape that would otherwise open an autolink", () => {
// `\<https://example.com>` renders as the literal text `<https://example.com>`.
// Dropping the backslash would publish a link the author escaped on purpose,
// and the escape half never escapes an autolink, so there is nothing to undo.
expect(unescapeAngleBracketEscapes("See \\<https://example.com> here")).toBe(
"See \\<https://example.com> here",
);
expect(unescapeAngleBracketEscapes("Mail \\<a.b@example.com> now")).toBe(
"Mail \\<a.b@example.com> now",
);
});
it("keeps an escape that would otherwise open a pointed link destination", () => {
expect(unescapeAngleBracketEscapes("[a](\\<my file.md>)")).toBe("[a](\\<my file.md>)");
});
it("still unescapes a tag that only looks like an autolink", () => {
expect(unescapeAngleBracketEscapes("\\<notascheme>")).toBe("<notascheme>");
// The scheme needs at least two characters, so this is not an autolink.
expect(unescapeAngleBracketEscapes("\\<x:y>")).toBe("<x:y>");
});
it("skips code spans and code blocks", () => {
expect(unescapeAngleBracketEscapes("Use `\\<name>` here")).toBe("Use `\\<name>` here");
expect(unescapeAngleBracketEscapes("```\n\\<name>\n```\n\\<after>")).toBe(
"```\n\\<name>\n```\n<after>",
);
expect(unescapeAngleBracketEscapes("intro\n\n \\<name>\n\nafter \\<x>")).toBe(
"intro\n\n \\<name>\n\nafter <x>",
);
});
it("is idempotent", () => {
const inputs = [
"Rename \\<name> here",
"a \\\\\\<name> b",
"Use `\\<name>` and \\<other>",
"```\n\\<name>\n```\n\\<after>",
];
for (const input of inputs) {
const once = unescapeAngleBracketEscapes(input);
expect(unescapeAngleBracketEscapes(once)).toBe(once);
}
});
});
describe("angle bracket escape round trip", () => {
const cases = [
"Rename <name> to the real name",
"Affected versions: <= v0.3.1",
"5. python3 sync.py --input <tmp> -- writes insights/<group>/*.md",
"a </close> and <!-- note --> and <?php",
"Use `<name>` but not <other>",
"```\n<name>\n```\n<after>",
"intro\n\n <name>\n\nafter <x>",
"See <https://example.com> and mail <a@b.com>, then <name>",
"[a](<my file.md>) then <name>",
"a \\\\<name> b",
"> quoted <name>",
"- item <name>\n- other <x>",
"para\n more <name> here",
"a `one\ntwo <x>` b <y>",
"plain prose with no brackets",
// An author's escaped autolink must survive an edit as literal text.
"See \\<https://example.com> here",
"Mail \\<a.b@example.com> now",
"",
];
it("returns the original markdown after escaping and unescaping", () => {
for (const input of cases) {
expect(unescapeAngleBracketEscapes(escapeUnsupportedAngleBrackets(input))).toBe(input);
}
});
it("normalizes a pre-escaped bracket to its clean form", () => {
// `\<name>` and `<name>` are the same literal text; the clean form is what
// this product stores, and the rewrite only happens on a real edit.
expect(unescapeAngleBracketEscapes(escapeUnsupportedAngleBrackets("Rename \\<name>"))).toBe(
"Rename <name>",
);
});
});