x/eta@v1.12.3/parse.ts

Embedded JS template engine for Node, Deno, and the browser. Lighweight, fast, and pluggable. Written in TypeScript
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import { ParseErr } from "./err.ts";import { trimWS } from "./utils.ts";
/* TYPES */
import type { EtaConfig } from "./config.ts";
export type TagType = "r" | "e" | "i" | "";
export interface TemplateObject { t: TagType; val: string;}
export type AstObject = string | TemplateObject;
/* END TYPES */
const templateLitReg = /`(?:\\[\s\S]|\${(?:[^{}]|{(?:[^{}]|{[^}]*})*})*}|(?!\${)[^\\`])*`/g;
const singleQuoteReg = /'(?:\\[\s\w"'\\`]|[^\n\r'\\])*?'/g;
const doubleQuoteReg = /"(?:\\[\s\w"'\\`]|[^\n\r"\\])*?"/g;
/** Escape special regular expression characters inside a string */
function escapeRegExp(string: string) { // From MDN return string.replace(/[.*+\-?^${}()|[\]\\]/g, "\\$&") // $& means the whole matched string ;}
export default function parse( str: string, config: EtaConfig,): Array<AstObject> { let buffer: Array<AstObject> = []; let trimLeftOfNextStr: string | false = false; let lastIndex = 0; const parseOptions = config.parse;
if (config.plugins) { for (let i = 0; i < config.plugins.length; i++) { const plugin = config.plugins[i]; if (plugin.processTemplate) { str = plugin.processTemplate(str, config); } } }
/* Adding for EJS compatibility */ if (config.rmWhitespace) { // Code taken directly from EJS // Have to use two separate replaces here as `^` and `$` operators don't // work well with `\r` and empty lines don't work well with the `m` flag. // Essentially, this replaces the whitespace at the beginning and end of // each line and removes multiple newlines. str = str.replace(/[\r\n]+/g, "\n").replace(/^\s+|\s+$/gm, ""); } /* End rmWhitespace option */
templateLitReg.lastIndex = 0; singleQuoteReg.lastIndex = 0; doubleQuoteReg.lastIndex = 0;
function pushString(strng: string, shouldTrimRightOfString?: string | false) { if (strng) { // if string is truthy it must be of type 'string'
strng = trimWS( strng, config, trimLeftOfNextStr, // this will only be false on the first str, the next ones will be null or undefined shouldTrimRightOfString, );
if (strng) { // replace \ with \\, ' with \' // we're going to convert all CRLF to LF so it doesn't take more than one replace
strng = strng.replace(/\\|'/g, "\\$&").replace(/\r\n|\n|\r/g, "\\n");
buffer.push(strng); } } }
const prefixes = [ parseOptions.exec, parseOptions.interpolate, parseOptions.raw, ].reduce(function ( accumulator, prefix, ) { if (accumulator && prefix) { return accumulator + "|" + escapeRegExp(prefix); } else if (prefix) { // accumulator is falsy return escapeRegExp(prefix); } else { // prefix and accumulator are both falsy return accumulator; } }, "");
const parseOpenReg = new RegExp( "([^]*?)" + escapeRegExp(config.tags[0]) + "(-|_)?\\s*(" + prefixes + ")?\\s*", "g", );
const parseCloseReg = new RegExp( "'|\"|`|\\/\\*|(\\s*(-|_)?" + escapeRegExp(config.tags[1]) + ")", "g", ); // TODO: benchmark having the \s* on either side vs using str.trim()
let m;
while ((m = parseOpenReg.exec(str))) { lastIndex = m[0].length + m.index;
const precedingString = m[1]; const wsLeft = m[2]; const prefix = m[3] || ""; // by default either ~, =, or empty
pushString(precedingString, wsLeft);
parseCloseReg.lastIndex = lastIndex; let closeTag; let currentObj: AstObject | false = false;
while ((closeTag = parseCloseReg.exec(str))) { if (closeTag[1]) { let content = str.slice(lastIndex, closeTag.index);
parseOpenReg.lastIndex = lastIndex = parseCloseReg.lastIndex;
trimLeftOfNextStr = closeTag[2];
const currentType: TagType = prefix === parseOptions.exec ? "e" : prefix === parseOptions.raw ? "r" : prefix === parseOptions.interpolate ? "i" : "";
currentObj = { t: currentType, val: content }; break; } else { const char = closeTag[0]; if (char === "/*") { const commentCloseInd = str.indexOf("*/", parseCloseReg.lastIndex);
if (commentCloseInd === -1) { ParseErr("unclosed comment", str, closeTag.index); } parseCloseReg.lastIndex = commentCloseInd; } else if (char === "'") { singleQuoteReg.lastIndex = closeTag.index;
const singleQuoteMatch = singleQuoteReg.exec(str); if (singleQuoteMatch) { parseCloseReg.lastIndex = singleQuoteReg.lastIndex; } else { ParseErr("unclosed string", str, closeTag.index); } } else if (char === '"') { doubleQuoteReg.lastIndex = closeTag.index; const doubleQuoteMatch = doubleQuoteReg.exec(str);
if (doubleQuoteMatch) { parseCloseReg.lastIndex = doubleQuoteReg.lastIndex; } else { ParseErr("unclosed string", str, closeTag.index); } } else if (char === "`") { templateLitReg.lastIndex = closeTag.index; const templateLitMatch = templateLitReg.exec(str); if (templateLitMatch) { parseCloseReg.lastIndex = templateLitReg.lastIndex; } else { ParseErr("unclosed string", str, closeTag.index); } } } } if (currentObj) { buffer.push(currentObj); } else { ParseErr("unclosed tag", str, m.index + precedingString.length); } }
pushString(str.slice(lastIndex, str.length), false);
if (config.plugins) { for (let i = 0; i < config.plugins.length; i++) { const plugin = config.plugins[i]; if (plugin.processAST) { buffer = plugin.processAST(buffer, config); } } }
return buffer;}