Dynamic route param values ignored for non-alpha(string) types

[jwhazel]

Repro steps

Create a function with dynamic route parameters that either have no constraints, or accept constraints other than alpha. The v4 example here will suffice: https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-http-webhook-trigger?tabs=python-v2%2Cisolated-process%2Cnodejs-v4%2Cfunctionsv2&pivots=programming-language-javascript#customize-the-http-endpoint

const { app } = require('@azure/functions');

app.http('httpTrigger1', {
    methods: ['GET'],
    authLevel: 'anonymous',
    route: 'products/{category:alpha}/{id:int?}',
    handler: async (request, context) => {
        const category = request.params.category;
        const id = request.params.id;

        return { body: `Category: ${category}, ID: ${id}` };
    },
});

Expected behavior

Given a route of products/abc/123, I expect the output to be Category: abc, ID: 123

Actual behavior

The actual output is Category: abc, ID: undefined

Related information

• It seems there's some sort of type checking going on behind the scenes and any value that is either a Number, Null, or Boolean in javascript doesn't get captured. E.g. products/abc/null or products/abc/true also return undefined. You can dump request.params and see that the keys simply don't exist.
• The existence of a constraint or optional qualifier ? doesn't seem to make a difference. I only included it above because that's a verbatim example from the documentation.
• I'm running version 4.0.5198 locally. I can confirm the same issue occurs in a production Azure environment with Node 20. I have not had the chance to test other versions of Core Tools or Node.

[ejizba]

Hi @jwhazel thanks for reporting - I'm going to close as duplicate of #285 (it was in a different repo, but I just transferred it to this repo). Please see this comment for the recommended workaround: #285 (comment)