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193/**
* Shared middleware matching code generator.
*
* Both the App Router RSC entry (app-dev-server.ts) and the Pages Router
* production entry (index.ts) need middleware matching logic inlined as
* generated JavaScript strings. This module provides a single source of
* truth to prevent the implementations from diverging.
*
* The regex detection guard (checking for "(" or "\\") is critical.
* Without it, dot-escaping corrupts regex patterns like
* /((?!api|_next).*), causing middleware to silently skip paths.
*/
/**
* Returns the generated JavaScript source for `__isSafeRegex` and `__safeRegExp`.
*
* @param style - "modern" emits const/let (for RSC entry), "es5" emits var (for prod entry)
*/
export function generateSafeRegExpCode(style: "modern" | "es5" = "modern"): string {
const v = style === "modern" ? "const" : "var";
const l = style === "modern" ? "let" : "var";
return `
function __isSafeRegex(pattern) {
${v} quantifierAtDepth = [];
${l} depth = 0;
${l} i = 0;
while (i < pattern.length) {
${v} ch = pattern[i];
if (ch === "\\\\") { i += 2; continue; }
if (ch === "[") {
i++;
while (i < pattern.length && pattern[i] !== "]") {
if (pattern[i] === "\\\\") i++;
i++;
}
i++;
continue;
}
if (ch === "(") {
depth++;
if (quantifierAtDepth.length <= depth) quantifierAtDepth.push(false);
else quantifierAtDepth[depth] = false;
i++;
continue;
}
if (ch === ")") {
${v} hadQ = depth > 0 && quantifierAtDepth[depth];
if (depth > 0) depth--;
${v} next = pattern[i + 1];
if (next === "+" || next === "*" || next === "{") {
if (hadQ) return false;
if (depth >= 0 && depth < quantifierAtDepth.length) quantifierAtDepth[depth] = true;
}
i++;
continue;
}
if (ch === "+" || ch === "*") {
if (depth > 0) quantifierAtDepth[depth] = true;
i++;
continue;
}
if (ch === "?") {
${v} prev = i > 0 ? pattern[i - 1] : "";
if (prev !== "+" && prev !== "*" && prev !== "?" && prev !== "}") {
if (depth > 0) quantifierAtDepth[depth] = true;
}
i++;
continue;
}
if (ch === "{") {
${l} j = i + 1;
while (j < pattern.length && /[\\d,]/.test(pattern[j])) j++;
if (j < pattern.length && pattern[j] === "}" && j > i + 1) {
if (depth > 0) quantifierAtDepth[depth] = true;
i = j + 1;
continue;
}
}
i++;
}
return true;
}
function __safeRegExp(pattern, flags) {
if (!__isSafeRegex(pattern)) {
console.warn("[vinext] Ignoring potentially unsafe regex pattern (ReDoS risk): " + pattern);
return null;
}
try { return new RegExp(pattern, flags); } catch { return null; }
}`;
}
/**
* Returns the generated JavaScript source for `__normalizePath`.
*
* This must be kept in sync with `normalizePath()` in `normalize-path.ts`.
* The inline version is used by codegen entries that can't import modules.
*
* @param style - "modern" emits const/let, "es5" emits var
*/
export function generateNormalizePathCode(style: "modern" | "es5" = "modern"): string {
const v = style === "modern" ? "const" : "var";
const l = style === "modern" ? "let" : "var";
return `
function __normalizePath(pathname) {
if (
pathname === "/" ||
(pathname.length > 1 &&
pathname[0] === "/" &&
!pathname.includes("//") &&
!pathname.includes("/./") &&
!pathname.includes("/../") &&
!pathname.endsWith("/.") &&
!pathname.endsWith("/.."))
) {
return pathname;
}
${v} segments = pathname.split("/");
${v} resolved = [];
for (${l} i = 0; i < segments.length; i++) {
${v} seg = segments[i];
if (seg === "" || seg === ".") continue;
if (seg === "..") { resolved.pop(); }
else { resolved.push(seg); }
}
return "/" + resolved.join("/");
}`;
}
/**
* Returns the generated JavaScript source for middleware pattern matching.
*
* This includes:
* - `matchMiddlewarePattern(pathname, pattern)` — matches a single pattern
* - `matchesMiddleware(pathname, matcher)` — matches the full matcher config
*
* The generated code depends on `__safeRegExp` being defined in the same scope
* (use `generateSafeRegExpCode` to emit it).
*
* @param style - "modern" emits const/let/arrow functions, "es5" emits var/function
*/
export function generateMiddlewareMatcherCode(style: "modern" | "es5" = "modern"): string {
const v = style === "modern" ? "const" : "var";
const l = style === "modern" ? "let" : "var";
const fn = style === "modern"
? (params: string, body: string) => `(${params}) => { ${body} }`
: (params: string, body: string) => `function(${params}) { ${body} }`;
// The pattern matching logic must be identical to matchPattern() in
// packages/vinext/src/server/middleware.ts. Any changes here must be
// mirrored there and vice versa.
return `
function matchMiddlewarePattern(pathname, pattern) {
// Regex patterns: if the pattern contains "(" or "\\" it's a regex —
// pass it through to RegExp directly WITHOUT dot-escaping.
// This guard prevents regex pattern corruption from dot-escaping.
if (pattern.includes("(") || pattern.includes("\\\\")) {
${v} re = __safeRegExp("^" + pattern + "$");
if (re) return re.test(pathname);
}
// Single-pass tokenizer (avoids chained .replace() flagged by CodeQL as
// incomplete sanitization — later passes could re-process earlier outputs).
${l} regexStr = "";
${v} tokenRe = /\\/:([\\w]+)\\*|\\/:([\\w]+)\\+|:([\\w]+)|[.]|[^/:.]+|./g;
${l} tok;
while ((tok = tokenRe.exec(pattern)) !== null) {
if (tok[1] !== undefined) { regexStr += "(?:/.*)?"; }
else if (tok[2] !== undefined) { regexStr += "(?:/.+)"; }
else if (tok[3] !== undefined) { regexStr += "([^/]+)"; }
else if (tok[0] === ".") { regexStr += "\\\\."; }
else { regexStr += tok[0]; }
}
${v} re2 = __safeRegExp("^" + regexStr + "$");
return re2 ? re2.test(pathname) : pathname === pattern;
}
function matchesMiddleware(pathname, matcher) {
if (!matcher) {
return true;
}
${v} patterns = [];
if (typeof matcher === "string") { patterns.push(matcher); }
else if (Array.isArray(matcher)) {
for (${v} m of matcher) {
if (typeof m === "string") patterns.push(m);
else if (m && typeof m === "object" && "source" in m) patterns.push(m.source);
}
}
return patterns.some(${fn("p", "return matchMiddlewarePattern(pathname, p);")});
}`;
}