🔨 (grapher) replace some enum types / TAS-709

[sophiamersmann]

Refactors Grapher types by replacing enums with compile-time-only types.

I introduced GrapherTabName in the previous PR, which is either a ChartTypeName or "WorldMap" or "Table". But enums currently can't be extended or merged, which means that I had to copy-paste all chart type names into GrapherTabName. As a result, TypeScript doesn't do a good job of type narrowing, forcing me to write (unnecessary) type assertions in many places.

This PR refactors ChartTypeName and other tab-related types so they don't use enums. However, I still wanted the convenience of a single object to access chart types, for example. To get that, the types are inferred from const objects:

const GRAPHER_CHART_TYPES = {
    LineChart: "LineChart",
    ScatterPlot: "ScatterPlot"
} as const

type GrapherChartType = keyof typeof GRAPHER_CHART_TYPES

I first did it the other way around (first defining the types, then using them for the objects), but it turns out the way it's done now leads to better type narrowing.

Newly introduced types:

• GrapherMapType: only "WorldMap"
• GrapherChartType: "LineChart", "ScatterPlot", etc. (without "WorldMap")
• GrapherChartOrMapType: GrapherChartType or GrapherMapType
• GrapherTabName: Internal tab names used in Grapher (a chart type name or "WorldMap" or "Table")
• GrapherTabOption: Grapher tab specified in the config that determines the default tab to show ("chart", "map" or "tab")
• GrapherTabQueryParam: Valid values for the tab query parameter in Grapher ("chart", "map", "line", "slope", etc.)

[sophiamersmann]

• 🎉 make line/slope switching available to authors / TAS-720 #4207 : 2 dependent PRs (#4210 , #4266 )
• 🎉 (slope) support facetting / TAS-734 #4247
• ✨ (slope) redesign / TAS-722 #4222
• 🎉 (slope) add tolerance / TAS-719 #4205
• 🎉 (slope) feature parity with line charts / TAS-708 #4192
• 🔨 (grapher) replace some enum types / TAS-709 #4170 👈 (View in Graphite)
• 🎉 (grapher) support multiple chart types / TAS-694 #4159
• master

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Refactor types in Grapher

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Edited: 2024-11-26 09:42:26 UTC
Execution time: 1.26 seconds

[sophiamersmann]

Merge activity

• Nov 26, 4:52 AM EST: A user started a stack merge that includes this pull request via Graphite.
• Nov 26, 4:55 AM EST: Graphite rebased this pull request as part of a merge.
• Nov 26, 4:56 AM EST: A user merged this pull request with Graphite.