File size: 7,556 Bytes
34810d2 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 | import { getLineInfo, parse } from "acorn";
import { decodeHTMLAttribute } from "entities";
type WidgetScriptSyntaxError = {
message: string;
/** Location in the supplied widget_code: 1-based line, 0-based UTF-16 column. */
line: number;
column: number;
snippet: string;
/** 1-based index among all scanned script elements, including skipped scripts. */
scriptIndex: number;
};
/** JavaScript MIME type essences per https://mimesniff.spec.whatwg.org/#javascript-mime-type. */
const JAVASCRIPT_MIME_ESSENCES = new Set([
"application/ecmascript",
"application/javascript",
"application/x-ecmascript",
"application/x-javascript",
"text/ecmascript",
"text/javascript",
"text/javascript1.0",
"text/javascript1.1",
"text/javascript1.2",
"text/javascript1.3",
"text/javascript1.4",
"text/javascript1.5",
"text/jscript",
"text/livescript",
"text/x-ecmascript",
"text/x-javascript",
]);
function scriptSourceType(attributes: string): "script" | "module" | undefined {
let type: string | undefined;
const attributePattern = /([^\s=/>]+)(?:\s*=\s*(?:"([^"]*)"|'([^']*)'|([^\s>]+)))?/g;
for (const attribute of attributes.matchAll(attributePattern)) {
const name = (attribute[1] ?? "").toLowerCase();
if (name === "src") {
return undefined;
}
if (name === "type") {
type ??= decodeHTMLAttribute(attribute[2] ?? attribute[3] ?? attribute[4] ?? "")
.trim()
.toLowerCase();
}
}
if (type === "module") {
return "module";
}
return !type || JAVASCRIPT_MIME_ESSENCES.has(type) ? "script" : undefined;
}
/** Finds a tag's closing bracket without interpreting quoted attribute values as markup. */
function findTagEnd(html: string, offset: number): number {
let quote = "";
for (let index = offset; index < html.length; index++) {
const char = html[index];
if (quote) {
if (char === quote) {
quote = "";
}
} else if (char === '"' || char === "'") {
quote = char;
} else if (char === ">") {
return index;
}
}
return html.length;
}
/**
* Script-looking text in double-escaped data cannot close the script element, and inside
* foreign (SVG) content a CDATA section keeps everything up to `]]>` as script text.
*/
function findRawTextEnd(html: string, start: number, name: string, foreign: boolean): number {
const tokens =
name === "script"
? foreign
? /<!\[CDATA\[|\]\]>|<!--|-->|<\/?script(?=[\t\n\f\r />])/gi
: /<!--|-->|<\/?script(?=[\t\n\f\r />])/gi
: new RegExp(`</${name}(?=[\\t\\n\\f\\r />])`, "gi");
tokens.lastIndex = start;
let state: "data" | "escaped" | "double-escaped" | "cdata" = "data";
for (const match of html.matchAll(tokens)) {
const token = match[0].toLowerCase();
if (state === "cdata") {
if (token === "]]>") {
state = "data";
}
} else if (token === "<![cdata[") {
state = "cdata";
} else if (token === "<!--" && state === "data") {
state = "escaped";
} else if (token === "-->") {
state = "data";
} else if (token.startsWith("</")) {
if (state !== "double-escaped") {
return match.index;
}
state = "escaped";
} else if (token === "<script" && state === "escaped") {
state = "double-escaped";
}
}
return html.length;
}
/**
* Tracks HTML contexts over the original input so script offsets never need normalization.
*
* Scope: SVG support covers CDATA-wrapped scripts, opaque CDATA sections, self-closing foreign
* elements, and foreignObject switching back to HTML rules. Character references inside foreign
* script text, CDATA sections interleaved with script text, and SVG nested inside foreignObject
* are intentionally not modeled; such input yields an explicit tool error, never a hosted widget
* with a script that cannot run.
*/
export function findWidgetScriptSyntaxError(
widgetCode: string,
): WidgetScriptSyntaxError | undefined {
const tagPattern = /<\/?([a-z][^\t\n\f\r />]*)/iy;
let position = 0;
let scriptIndex = 0;
let svgDepth = 0;
let foreignObjectDepth = 0;
while (position < widgetCode.length) {
const start = widgetCode.indexOf("<", position);
if (start < 0) {
break;
}
position = start + 1;
if (widgetCode.startsWith("<!--", start)) {
const end = widgetCode.indexOf("-->", start + 4);
position = end < 0 ? widgetCode.length : end + 3;
continue;
}
// foreignObject is an HTML integration point, so its children follow HTML rules again.
const foreign = svgDepth > 0 && foreignObjectDepth === 0;
if (foreign && widgetCode.startsWith("<![CDATA[", start)) {
const end = widgetCode.indexOf("]]>", start + 9);
position = end < 0 ? widgetCode.length : end + 3;
continue;
}
tagPattern.lastIndex = start;
const tag = tagPattern.exec(widgetCode);
if (!tag) {
if (widgetCode[position] === "!" || widgetCode[position] === "/") {
position = findTagEnd(widgetCode, position + 1) + 1;
}
continue;
}
const attributesStart = tagPattern.lastIndex;
const tagEnd = findTagEnd(widgetCode, attributesStart);
position = tagEnd + 1;
if (tagEnd === widgetCode.length) {
continue;
}
const name = (tag[1] ?? "").toLowerCase();
const closing = widgetCode[start + 1] === "/";
const selfClosing = widgetCode[tagEnd - 1] === "/";
if (name === "svg") {
svgDepth = closing ? Math.max(0, svgDepth - 1) : svgDepth + (selfClosing ? 0 : 1);
} else if (name === "foreignobject" && svgDepth > 0) {
foreignObjectDepth = closing
? Math.max(0, foreignObjectDepth - 1)
: foreignObjectDepth + (selfClosing ? 0 : 1);
}
if (closing) {
continue;
}
if (name === "plaintext") {
break;
}
if (!/^(?:script|style|textarea|title|xmp|iframe|noembed|noframes|noscript)$/.test(name)) {
continue;
}
// Foreign content honors self-closing start tags; HTML content ignores the slash.
if (foreign && selfClosing) {
continue;
}
let bodyStart = position;
const bodyEnd = findRawTextEnd(widgetCode, bodyStart, name, foreign);
const closingBracket = bodyEnd < widgetCode.length ? widgetCode.indexOf(">", bodyEnd) : -1;
position = closingBracket < 0 ? widgetCode.length : closingBracket + 1;
if (name !== "script") {
continue;
}
scriptIndex++;
const sourceType = scriptSourceType(widgetCode.slice(attributesStart, tagEnd));
if (!sourceType) {
continue;
}
let body = widgetCode.slice(bodyStart, bodyEnd);
const trimmed = body.trim();
if (foreign && trimmed.startsWith("<![CDATA[") && trimmed.endsWith("]]>")) {
bodyStart += body.length - body.trimStart().length + "<![CDATA[".length;
body = trimmed.slice("<![CDATA[".length, -"]]>".length);
}
try {
parse(body, { ecmaVersion: "latest", sourceType });
} catch (error) {
if (!(error instanceof SyntaxError) || !("pos" in error) || typeof error.pos !== "number") {
throw error;
}
const offset = bodyStart + error.pos;
const { line, column } = getLineInfo(widgetCode, offset);
const snippet = (widgetCode.slice(offset - column).split(/[\r\n\u2028\u2029]/u, 1)[0] ?? "")
.trim()
.slice(0, 160);
return {
message: error.message.replace(/ \(\d+:\d+\)$/u, "").slice(0, 200),
line,
column,
snippet,
scriptIndex,
};
}
}
return undefined;
}
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