lookbehind not supported on safari < 17

[rhysburnie]

Hi! 👋

Firstly, thanks for your work on this project! 🙂

Today I used patch-package to patch anchorme@3.0.5 for the project I'm working on.

Here is the diff that solved my problem:

diff --git a/node_modules/anchorme/dist/node/regex.js b/node_modules/anchorme/dist/node/regex.js
index 817f906..573a757 100644
--- a/node_modules/anchorme/dist/node/regex.js
+++ b/node_modules/anchorme/dist/node/regex.js
@@ -15,7 +15,14 @@ var fqdn = "(((".concat(protocol, ")?(").concat(domain, "|").concat(ipv4, ")(?=\
 exports.email = "\\b(mailto:)?".concat(emailAddress, "@(").concat(domain, "|").concat(ipv4, ")");
 exports.url = "(".concat(fqdn, ")").concat(path, "?");
 exports.file = "(file:\\/\\/\\/)(?:[a-z]+:(?:\\/|\\\\)+)?([\\w.]+(?:[\\/\\\\]?)+)+";
-exports.final = "(?<=\\b|_)((".concat(exports.email, ")|(").concat(exports.file, ")|(").concat(exports.url, "))(\\b)?");
+
+try {
+  new RegExp('(?<=\\b|_)'); // safari < 17 doesnt like this
+  exports.final = "(?<=\\b|_)((".concat(exports.email, ")|(").concat(exports.file, ")|(").concat(exports.url, "))(\\b)?");
+} catch(err) {
+  exports.final = "(?:\\b|_)((".concat(exports.email, ")|(").concat(exports.file, ")|(").concat(exports.url, "))(\\b)?");
+}
+
 exports.finalRegex = new RegExp(exports.final, "gi");
 // for validation purposes
 exports.ipRegex = new RegExp("^(".concat(ipv4, "|").concat(ipv6, ")$"), "i");

This issue body was partially generated by patch-package.

[rhysburnie]

I'm no regExp expert I was just going by this for rough equiv of look behind https://stackoverflow.com/a/74994273/738957
This was crashing our entire app, if this fix has a side effect on some anchorme links its preferable over an entire crash.
However if there is a better fix would be good to know.

[alexcorvi]

Please check the latest version 3.0.7

[lionel-rowe]

Current fix gives wrong capture group results, as there are more capture groups in the lookaround-supporting regex than there are in the compat-mode regex:

const OriginalRegExp = globalThis.RegExp;

class SafariRegExp extends OriginalRegExp {
    constructor(pattern, flags) {
        super(pattern, flags)
        if (String(pattern).includes('(?<=')) {
            throw new SyntaxError('idk what (?<= even means')
        }
    }
}

globalThis.RegExp = SafariRegExp

const anchorme = (await import('https://esm.sh/v135/anchorme@3.0.8')).default
console.info(
    anchorme.list(
        `https://example.xyz example.com user@email.com file:///filename.txt 192.168.1.1`,
        false,
    )
)

// expected:
[
	{ start: 0, end: 19, string: 'https://example.xyz', isURL: true, protocol: 'https://', /* ... */ },
	{ start: 20, end: 31, string: 'example.com', isURL: true, protocol: undefined, /* ... */ },
	{ start: 32, end: 46, string: 'user@email.com', isEmail: true, local: 'user', /* ... */ },
	{ start: 47, end: 67, string: 'file:///filename.txt', isFile: true, protocol: 'file:///', /* ... */ },
	{ start: 68, end: 79, string: '192.168.1.1', isURL: true, protocol: undefined, /* ... */ },	
]
// actual:
[
	{ start: 0, end: 19, string: 'https://example.xyz', reason: 'unknown' },
	{ start: 20, end: 31, string: 'example.com', reason: 'unknown' },
	{ start: 32, end: 46, string: 'user@email.com', reason: 'unknown' },
	{ start: 47, end: 67, string: 'file:///filename.txt', isURL: true, protocol: undefined, /* ... */ },
	{ start: 68, end: 79, string: '192.168.1.1', reason: 'unknown' },	
]

I'll have a PR up with a fix shortly — I think with the fix, reason: "unknown" can also be removed entirely as it should never occur.