Simon Lydell f80463120b babel-code-frame: Handle code with tabs
Previously, the `^` marker was misaligned if the line above contained tabs.

Fixes T7282.

Note: This commit handles a very subtle edge-case differently: When the passed
in column number is larger than the length of the line. Previously, the `^`
marker would be faithfully placed at that exact column number. Now, it is placed
at the end of the line instead (after the last character of the line to be
precise). Ideally, we should define what should happen in edge cases, but that's
out of scope for this PR.
2016-04-11 15:46:32 +02:00

119 lines
2.6 KiB
JavaScript

import jsTokens from "js-tokens";
import esutils from "esutils";
import chalk from "chalk";
/**
* Chalk styles for token types.
*/
let defs = {
string: chalk.red,
punctuator: chalk.bold,
curly: chalk.green,
parens: chalk.blue.bold,
square: chalk.yellow,
keyword: chalk.cyan,
number: chalk.magenta,
regex: chalk.magenta,
comment: chalk.grey,
invalid: chalk.inverse
};
/**
* RegExp to test for newlines in terminal.
*/
const NEWLINE = /\r\n|[\n\r\u2028\u2029]/;
/**
* Get the type of token, specifying punctuator type.
*/
function getTokenType(match) {
let token = jsTokens.matchToToken(match);
if (token.type === "name" && esutils.keyword.isReservedWordES6(token.value)) {
return "keyword";
}
if (token.type === "punctuator") {
switch (token.value) {
case "{":
case "}":
return "curly";
case "(":
case ")":
return "parens";
case "[":
case "]":
return "square";
}
}
return token.type;
}
/**
* Highlight `text`.
*/
function highlight(text: string) {
return text.replace(jsTokens, function (...args) {
let type = getTokenType(args);
let colorize = defs[type];
if (colorize) {
return args[0].split(NEWLINE).map((str) => colorize(str)).join("\n");
} else {
return args[0];
}
});
}
/**
* Create a code frame, adding line numbers, code highlighting, and pointing to a given position.
*/
export default function (
rawLines: string,
lineNumber: number,
colNumber: ?number,
opts: Object = {},
): string {
colNumber = Math.max(colNumber, 0);
let highlighted = opts.highlightCode && chalk.supportsColor;
if (highlighted) rawLines = highlight(rawLines);
let lines = rawLines.split(NEWLINE);
let start = Math.max(lineNumber - 3, 0);
let end = Math.min(lines.length, lineNumber + 3);
if (!lineNumber && !colNumber) {
start = 0;
end = lines.length;
}
let numberMaxWidth = String(end).length;
let frame = lines.slice(start, end).map((line, index) => {
let number = start + 1 + index;
let paddedNumber = ` ${number}`.slice(-numberMaxWidth);
let gutter = ` ${paddedNumber} | `;
if (number === lineNumber) {
let markerLine = "";
if (colNumber) {
let markerSpacing = line.slice(0, colNumber - 1).replace(/[^\t]/g, " ");
markerLine =`\n ${gutter.replace(/\d/g, " ")}${markerSpacing}^`;
}
return `>${gutter}${line}${markerLine}`;
} else {
return ` ${gutter}${line}`;
}
}).join("\n");
if (highlighted) {
return chalk.reset(frame);
} else {
return frame;
}
}