Fix/issue 64 promise false class

[TudorGR]

Summary

Fixes #64 the bug where a Promise resolving to false would incorrectly add a class name to an element.

The Problem

When using class="${{dotted}}" where dotted = Promise.resolve(false), the class was being added even though the promise resolved to false. This happened because ClassObjectSink was checking if the Promise object itself was truthy (it always is) instead of waiting for the resolved value.

The Solution

Modified ClassObjectSink to:

1. Check if a value is a future (Promise or Observable) using isFuture()
2. If it's a future, defer the add/remove decision until after it resolves
3. Make the decision based on the resolved value instead of the Promise object

Changes

• src/sinks/class-sink.ts: Added isFuture check and conditional logic
• src/sinks/class-sink.test.ts: Added 3 test cases covering promises resolving to false/true

Testing

All tests pass ✅:

• New test: Promise resolving to false does NOT add class
• New test: Promise resolving to true DOES add class
• New test: Direct false value does NOT add class (baseline)
• All existing tests continue to pass (9/9 class-sink tests, 143/143 total)

Example

const dotted = Promise.resolve(false);
rml`<div class="${{dotted}}">should NOT be dotted</div>` // ✅ Now works correctly!

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[dariomannu]

Can you rebase your code, please, as this stuff has already been merged from another PR?

[dariomannu]

This is great, can we just give these a little bit of structure, please, so it's easy to see how these are organised, what they are covering and ultimately if there's anything that might be missing, or if new tests need adding, where exactly should those be put?

describe('when a property of the object is a present value', () => {
	...
});

describe('when a property of the object is a future value', () => {

	describe('when it resolves/emits true', () => {

		it('should add a class corresponding to the property name', () => {

	describe('when it resolves/emits false () => {

		it('should not add a class corresponding to the property name', () => {

[dariomannu]

any chance we can use the subscribe function, here, instead? That should also flatten promises/observables down

[dariomannu]

adding hacktoberfest-accepted label, as the fix is fine, even if we're just adding a few minor improvements and finessing, in case you're participating in Hacktoberfest...

[dariomannu]

was it not feasible to use subscribe?

[TudorGR]

I looked into using subscribe, but it requires a node parameter as the first argument:

export const subscribe = (node: Node, source: MaybeFuture<T>, next: ...) => { ... }

Since we're inside the forEach callback and don't have the node in scope at that point, asap seemed like the right fit. It's also the pattern used in other sinks like content-sink.ts, dataset-sink.ts, and style-sink.ts.

Should I refactor this differently?

[dariomannu]

oh, yeah, you're right... good point.
So, we're all good, then, the rest looks great, LGTM!

[dariomannu]

@TudorGR all good and working, great work!
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