使用 Node.js 我验证了 xml 模式的 xml 模式，但它失败了。 我不知道为什么

Question

Here is the code I wrote:

const request = require('request');
const libXMLJS = require("libxmljs");

request.get('https://www.w3.org/2009/XMLSchema/XMLSchema.xsd', function (error, response, body) {
    if (!error && response.statusCode === 200) {
        // is it well-formed?
        try {
            libXMLJS.parseXml(body);
        } catch(e) {
            console.log('schema schema not well-formed');
            return;
        }
        console.log('schema schema well-formed');

        // Is the schema schema a valid schema?
        const schemaSchema = libXMLJS.parseXml(body);
        try {
            schemaSchema.validate(schemaSchema)
        } catch(e) {
            console.log('schema schema not valid schema');
            return;
        }
        console.log('schema schema valid schema');
    }
});

The output was:

schema schema well-formed
schema schema not valid schema

This doesn't make sense to me.

Answer 1

Why are you ignoring the information in the exception e ? It's not surprising you don't know why it failed if you don't look at the error information.

Having said that, the schema document at https://www.w3.org/2009/XMLSchema/XMLSchema.xsd appears to be a schema for XSD 1.1 (though probably not the final one, since the XSD 1.1 recommendation was published in 2012) and the libXML processor only supports XSD 1.0.

(I'm not aware of an XSD 1.1 processor for Node.js. One day perhaps we'll include schema processing in the Saxon-JS product, but it's not there yet.)