getAttribute() for data attributes does not work due to normalization for props about lwc

[caridy]

@diervo I have added some tests to validate that this is actually fixed.

[caridy]

@diervo can you clarify? the code in question is:

    getAttribute(attrName: string): string | null {
        // logging errors for experimental and special attributes
        if (process.env.NODE_ENV !== 'production') {
            const vm = this[ViewModelReflection];
            assert.vm(vm);
            if (isString(attrName)) {
                const propName = getPropNameFromAttrName(attrName);
                const info = getGlobalHTMLPropertiesInfo();
                if (info[propName] && info[propName].attribute) {
                    const { error, experimental } = info[propName];
                    if (error) {
                        assert.logError(error);
                    } else if (experimental) {
                        assert.logError(`Attribute \`${attrName}\` is an experimental attribute that is not standardized or supported by all browsers. Property "${propName}" and attribute "${attrName}" are ignored.`);
                    }
                }
            }
        }

        return getAttribute.apply(getLinkedElement(this), ArraySlice.call(arguments));
    }

the check that you're questioning is only in dev mode and only cares about well-known attributes/properties. dataId is an unknown property, therefore no error will be issued, and the last line of the method, which is the real important part, is still doing the job. This is on master today. Maybe this issue is not relevant any more.

[byao]

@diervo pls provide more details

[caridy]

closed by #468