[Feature] filtering an array of series by type should return the right TypeScript Type

[Joaveinz]

Version

5.2.2

Link to Minimal Reproduction

No response

Steps to Reproduce

1. Have an option with multiple series
2. filter the option series by type

Current Behavior

I want to toggle the "smooth" property of my chart series.

Currently, I have to use this if statement:

inside the foreach statement, set is of type SeriesOption$1
Inside the if statement, set is of type LineSeriesOption$1

option.value.series.forEach((set) => {
    if (set.type === "line") {
        set.smooth = !set.smooth;
    }
});

Expected Behavior

I would like the filter to return LineSeriesOption$1, so I can use the following code:

option.value.series.filter((set) => set.type === "line").forEach((set) => {
    set.smooth = !set.smooth;
});

Environment

- OS: macOS Monterey M1 2020
- Browser: Chrome
- Framework: Vue 3 + vue-echarts library

Any additional comments?

Just a note, not high priority for me.

[pissang]

Seems it's the limitation of TypeScript. There is no type narrowing for the filter method. See microsoft/TypeScript#20812 (comment)