@modelcontextprotocol/sdk
Version:
Model Context Protocol implementation for TypeScript
243 lines • 8.86 kB
JavaScript
;
// Claude-authored implementation of RFC 6570 URI Templates
Object.defineProperty(exports, "__esModule", { value: true });
exports.UriTemplate = void 0;
const MAX_TEMPLATE_LENGTH = 1000000; // 1MB
const MAX_VARIABLE_LENGTH = 1000000; // 1MB
const MAX_TEMPLATE_EXPRESSIONS = 10000;
const MAX_REGEX_LENGTH = 1000000; // 1MB
class UriTemplate {
/**
* Returns true if the given string contains any URI template expressions.
* A template expression is a sequence of characters enclosed in curly braces,
* like {foo} or {?bar}.
*/
static isTemplate(str) {
// Look for any sequence of characters between curly braces
// that isn't just whitespace
return /\{[^}\s]+\}/.test(str);
}
static validateLength(str, max, context) {
if (str.length > max) {
throw new Error(`${context} exceeds maximum length of ${max} characters (got ${str.length})`);
}
}
get variableNames() {
return this.parts.flatMap(part => (typeof part === 'string' ? [] : part.names));
}
constructor(template) {
UriTemplate.validateLength(template, MAX_TEMPLATE_LENGTH, 'Template');
this.template = template;
this.parts = this.parse(template);
}
toString() {
return this.template;
}
parse(template) {
const parts = [];
let currentText = '';
let i = 0;
let expressionCount = 0;
while (i < template.length) {
if (template[i] === '{') {
if (currentText) {
parts.push(currentText);
currentText = '';
}
const end = template.indexOf('}', i);
if (end === -1)
throw new Error('Unclosed template expression');
expressionCount++;
if (expressionCount > MAX_TEMPLATE_EXPRESSIONS) {
throw new Error(`Template contains too many expressions (max ${MAX_TEMPLATE_EXPRESSIONS})`);
}
const expr = template.slice(i + 1, end);
const operator = this.getOperator(expr);
const exploded = expr.includes('*');
const names = this.getNames(expr);
const name = names[0];
// Validate variable name length
for (const name of names) {
UriTemplate.validateLength(name, MAX_VARIABLE_LENGTH, 'Variable name');
}
parts.push({ name, operator, names, exploded });
i = end + 1;
}
else {
currentText += template[i];
i++;
}
}
if (currentText) {
parts.push(currentText);
}
return parts;
}
getOperator(expr) {
const operators = ['+', '#', '.', '/', '?', '&'];
return operators.find(op => expr.startsWith(op)) || '';
}
getNames(expr) {
const operator = this.getOperator(expr);
return expr
.slice(operator.length)
.split(',')
.map(name => name.replace('*', '').trim())
.filter(name => name.length > 0);
}
encodeValue(value, operator) {
UriTemplate.validateLength(value, MAX_VARIABLE_LENGTH, 'Variable value');
if (operator === '+' || operator === '#') {
return encodeURI(value);
}
return encodeURIComponent(value);
}
expandPart(part, variables) {
if (part.operator === '?' || part.operator === '&') {
const pairs = part.names
.map(name => {
const value = variables[name];
if (value === undefined)
return '';
const encoded = Array.isArray(value)
? value.map(v => this.encodeValue(v, part.operator)).join(',')
: this.encodeValue(value.toString(), part.operator);
return `${name}=${encoded}`;
})
.filter(pair => pair.length > 0);
if (pairs.length === 0)
return '';
const separator = part.operator === '?' ? '?' : '&';
return separator + pairs.join('&');
}
if (part.names.length > 1) {
const values = part.names.map(name => variables[name]).filter(v => v !== undefined);
if (values.length === 0)
return '';
return values.map(v => (Array.isArray(v) ? v[0] : v)).join(',');
}
const value = variables[part.name];
if (value === undefined)
return '';
const values = Array.isArray(value) ? value : [value];
const encoded = values.map(v => this.encodeValue(v, part.operator));
switch (part.operator) {
case '':
return encoded.join(',');
case '+':
return encoded.join(',');
case '#':
return '#' + encoded.join(',');
case '.':
return '.' + encoded.join('.');
case '/':
return '/' + encoded.join('/');
default:
return encoded.join(',');
}
}
expand(variables) {
let result = '';
let hasQueryParam = false;
for (const part of this.parts) {
if (typeof part === 'string') {
result += part;
continue;
}
const expanded = this.expandPart(part, variables);
if (!expanded)
continue;
// Convert ? to & if we already have a query parameter
if ((part.operator === '?' || part.operator === '&') && hasQueryParam) {
result += expanded.replace('?', '&');
}
else {
result += expanded;
}
if (part.operator === '?' || part.operator === '&') {
hasQueryParam = true;
}
}
return result;
}
escapeRegExp(str) {
return str.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
}
partToRegExp(part) {
const patterns = [];
// Validate variable name length for matching
for (const name of part.names) {
UriTemplate.validateLength(name, MAX_VARIABLE_LENGTH, 'Variable name');
}
if (part.operator === '?' || part.operator === '&') {
for (let i = 0; i < part.names.length; i++) {
const name = part.names[i];
const prefix = i === 0 ? '\\' + part.operator : '&';
patterns.push({
pattern: prefix + this.escapeRegExp(name) + '=([^&]+)',
name
});
}
return patterns;
}
let pattern;
const name = part.name;
switch (part.operator) {
case '':
pattern = part.exploded ? '([^/]+(?:,[^/]+)*)' : '([^/,]+)';
break;
case '+':
case '#':
pattern = '(.+)';
break;
case '.':
pattern = '\\.([^/,]+)';
break;
case '/':
pattern = '/' + (part.exploded ? '([^/]+(?:,[^/]+)*)' : '([^/,]+)');
break;
default:
pattern = '([^/]+)';
}
patterns.push({ pattern, name });
return patterns;
}
match(uri) {
UriTemplate.validateLength(uri, MAX_TEMPLATE_LENGTH, 'URI');
let pattern = '^';
const names = [];
for (const part of this.parts) {
if (typeof part === 'string') {
pattern += this.escapeRegExp(part);
}
else {
const patterns = this.partToRegExp(part);
for (const { pattern: partPattern, name } of patterns) {
pattern += partPattern;
names.push({ name, exploded: part.exploded });
}
}
}
pattern += '$';
UriTemplate.validateLength(pattern, MAX_REGEX_LENGTH, 'Generated regex pattern');
const regex = new RegExp(pattern);
const match = uri.match(regex);
if (!match)
return null;
const result = {};
for (let i = 0; i < names.length; i++) {
const { name, exploded } = names[i];
const value = match[i + 1];
const cleanName = name.replace('*', '');
if (exploded && value.includes(',')) {
result[cleanName] = value.split(',');
}
else {
result[cleanName] = value;
}
}
return result;
}
}
exports.UriTemplate = UriTemplate;
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