🔨 add empty arrays to the default grapher config (#4294)

Empty arrays are not currently included in Grapher's default config object that is derived from the schema. That's a bit of a foot gun, so I added them now.

For context: When I implemented inheritance, I decided to keep empty arrays out of the default config since all defaults ended up in the `fullConfig` of each chart and that would have been unnecessarily verbose. But now that we're not doing that anymore, I can't think of a downside of also including the default values for arrays.

This has two nice effects:
- It used to be important that Grapher serialises empty arrays, so that a parent value can be overwritten with that empty array (e.g. if a parent has a related question that a child doesn't need). Now we can rely on these values being present in the default config.
- Another nice effect is that we can simplify a number of tests like this one where `selectedEntityNames` was always serialised, even for an empty Grapher:

https://github.com/owid/owid-grapher/blob/28ba2e4c036d0eb6156a4609add48f9e6077a764/packages/%40ourworldindata/grapher/src/core/Grapher.jsdom.test.ts#L92-L98

adminSiteClient/AbstractChartEditor.ts

@@ -106,7 +106,7 @@ export abstract class AbstractChartEditor<
     /** patch config merged with parent config */
     @computed get fullConfig(): GrapherInterface {
         if (!this.activeParentConfig) return this.liveConfig
-        return mergeGrapherConfigs(this.activeParentConfig, this.liveConfig)
+        return mergeGrapherConfigs(this.activeParentConfig, this.patchConfig)
     }
 
     /** parent config currently applied to grapher */

devTools/schema/generate-default-object-from-schema.ts

@@ -4,6 +4,8 @@ import parseArgs from "minimist"
 import fs from "fs-extra"
 import { range } from "lodash"
 
+const TEMPLATE_FILENAME = "./devTools/schema/template"
+
 const schemaVersionRegex =
     /https:\/\/files\.ourworldindata\.org\/schemas\/grapher-schema\.(?<version>\d{3})\.json/m
 const getSchemaVersion = (config: Record<string, any>): string =>
@@ -58,23 +60,23 @@ async function main(parsedArgs: parseArgs.ParsedArgs) {
 
     // save as ts file if requested
     if (parsedArgs["save-ts"]) {
+        const template = fs.readFileSync(TEMPLATE_FILENAME, "utf8")
+
         const latestVersion = getSchemaVersion(defaultConfig)
         const outdatedVersionsAsInts = range(1, parseInt(latestVersion))
         const outdatedVersions = outdatedVersionsAsInts.map((versionNumber) =>
             versionNumber.toString().padStart(3, "0")
         )
 
         const out = parsedArgs["save-ts"]
-        const content = `// THIS IS A GENERATED FILE, DO NOT EDIT DIRECTLY
-
-// GENERATED BY devTools/schema/generate-default-object-from-schema.ts
-
-import { GrapherInterface } from "@ourworldindata/types"
-
-export const latestSchemaVersion = "${latestVersion}" as const
-export const outdatedSchemaVersions = ${toArrayString(outdatedVersions)} as const
+        const content = template
+            .replace("{{LATEST_SCHEMA_VERSION}}", latestVersion.toString())
+            .replace(
+                "{{OUTDATED_SCHEMA_VERSIONS}}",
+                toArrayString(outdatedVersions)
+            )
+            .replace("{{DEFAULT_GRAPHER_CONFIG}}", defaultConfigJSON)
 
-export const defaultGrapherConfig = ${defaultConfigJSON} as GrapherInterface`
         fs.outputFileSync(out, content)
     }
 

devTools/schema/template

@@ -0,0 +1,10 @@
+// THIS IS A GENERATED FILE, DO NOT EDIT DIRECTLY
+
+// GENERATED BY devTools/schema/generate-default-object-from-schema.ts
+
+import { GrapherInterface } from "@ourworldindata/types"
+
+export const latestSchemaVersion = "{{LATEST_SCHEMA_VERSION}}" as const
+export const outdatedSchemaVersions = {{OUTDATED_SCHEMA_VERSIONS}} as const
+
+export const defaultGrapherConfig = {{DEFAULT_GRAPHER_CONFIG}} as GrapherInterface

packages/@ourworldindata/grapher/src/core/Grapher.jsdom.test.ts

@@ -79,10 +79,6 @@ it("can get dimension slots", () => {
 it("an empty Grapher serializes to an object that includes only the schema", () => {
     expect(new Grapher().toObject()).toEqual({
         $schema: latestGrapherConfigSchema,
-
-        // TODO: ideally, these are not serialised for an empty object
-        selectedEntityNames: [],
-        focusedSeriesNames: [],
     })
 })
 
@@ -93,20 +89,12 @@ it("a bad chart type does not crash grapher", () => {
     expect(new Grapher(input).toObject()).toEqual({
         ...input,
         $schema: latestGrapherConfigSchema,
-
-        // TODO: ideally, these are not serialised for an empty object
-        selectedEntityNames: [],
-        focusedSeriesNames: [],
     })
 })
 
 it("does not preserve defaults in the object (except for the schema)", () => {
     expect(new Grapher({ tab: GRAPHER_TAB_OPTIONS.chart }).toObject()).toEqual({
         $schema: latestGrapherConfigSchema,
-
-        // TODO: ideally, these are not serialised for an empty object
-        selectedEntityNames: [],
-        focusedSeriesNames: [],
     })
 })
 

packages/@ourworldindata/grapher/src/core/Grapher.tsx

@@ -437,15 +437,14 @@ export class Grapher
         [entityName: string]: string | undefined
     } = {}
 
-    // Initializing arrays with `undefined` ensures that empty arrays get serialised
-    @observable selectedEntityNames?: EntityName[] = undefined
+    @observable selectedEntityNames: EntityName[] = []
+    @observable focusedSeriesNames: SeriesName[] = []
     @observable excludedEntities?: number[] = undefined
     /** IncludedEntities are usually empty which means use all available entities. When
         includedEntities is set it means "only use these entities". excludedEntities
         are evaluated afterwards and can still remove entities even if they were included before.
      */
     @observable includedEntities?: number[] = undefined
-    @observable focusedSeriesNames?: SeriesName[] = undefined
     @observable comparisonLines?: ComparisonLineConfig[] = undefined // todo: Persistables?
     @observable relatedQuestions?: RelatedQuestionsConfig[] = undefined // todo: Persistables?
 

packages/@ourworldindata/grapher/src/schema/defaultGrapherConfig.ts

@@ -30,6 +30,8 @@ export const defaultGrapherConfig = {
         time: "latest",
     },
     maxTime: "latest",
+    selectedEntityNames: [],
+    focusedSeriesNames: [],
     yAxis: {
         removePointsOutsideDomain: false,
         scaleType: "linear",
@@ -54,11 +56,13 @@ export const defaultGrapherConfig = {
     selectedFacetStrategy: "none",
     invertColorScheme: false,
     hideRelativeToggle: true,
+    comparisonLines: [],
     logo: "owid",
     entityType: "country or region",
     facettingLabelByYVariables: "metric",
     addCountryMode: "add-country",
     compareEndPointsOnly: false,
+    relatedQuestions: [],
     chartTypes: ["LineChart"],
     hasMapTab: false,
     stackMode: "absolute",
@@ -68,6 +72,7 @@ export const defaultGrapherConfig = {
         time: false,
         changeInPrefix: false,
     },
+    excludedEntities: [],
     xAxis: {
         removePointsOutsideDomain: false,
         scaleType: "linear",
@@ -85,6 +90,7 @@ export const defaultGrapherConfig = {
     sortBy: "total",
     sortOrder: "desc",
     hideFacetControl: true,
+    includedEntities: [],
     entityTypePlural: "countries and regions",
     missingDataStrategy: "auto",
 } as GrapherInterface

packages/@ourworldindata/grapher/src/schema/grapher-schema.006.yaml

@@ -101,6 +101,7 @@ properties:
     selectedEntityNames:
         type: array
         description: The initial selection of entities
+        default: []
         items:
             type:
                 - string
@@ -109,6 +110,7 @@ properties:
         description: |
             The initially focused chart elements. Is either a list of entity or variable names.
             Only works for line and slope charts for now.
+        default: []
         items:
             type:
                 - string
@@ -195,6 +197,7 @@ properties:
     comparisonLines:
         description: List of vertical comparison lines to draw
         type: array
+        default: []
         items:
             type: object
             properties:
@@ -361,6 +364,7 @@ properties:
     relatedQuestions:
         type: array
         description: Links to related questions
+        default: []
         items:
             type: object
             properties:
@@ -428,6 +432,7 @@ properties:
     excludedEntities:
         type: array
         description: Entities that should be excluded from the chart
+        default: []
         items:
             type: integer
             minimum: 0
@@ -493,6 +498,7 @@ properties:
     includedEntities:
         type: array
         description: Entities to include. Opposite of excludedEntities. If this is set then all entities not specified here are excluded.
+        default: []
         items:
             type: number
     entityTypePlural: