✨ (grapher) ignore empty objects when merging configs

owid · Aug 8, 2024 · d9f616a · d9f616a
1 parent 9f6b00e
commit d9f616a
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Showing 2 changed files with 45 additions and 8 deletions.
diff --git a/packages/@ourworldindata/utils/src/grapherConfigUtils.test.ts b/packages/@ourworldindata/utils/src/grapherConfigUtils.test.ts
@@ -141,7 +141,7 @@ describe(mergeGrapherConfigs, () => {
         ).toThrowError()
     })
 
-    it("excludes $schema, id, slug, version and isPublished from inheritance", () => {
+    it("excludes id, slug, version and isPublished from inheritance", () => {
         expect(
             mergeGrapherConfigs(
                 {
@@ -165,7 +165,37 @@ describe(mergeGrapherConfigs, () => {
                 },
                 { slug: "child-slug", version: 1, title: "Title B" }
             )
-        ).toEqual({ slug: "child-slug", version: 1, title: "Title B" })
+        ).toEqual({
+            slug: "child-slug",
+            version: 1,
+            title: "Title B",
+        })
+    })
+
+    it("ignores empty objects", () => {
+        expect(
+            mergeGrapherConfigs(
+                {
+                    title: "Parent title",
+                    subtitle: "Parent subtitle",
+                },
+                {
+                    $schema: "004",
+                    id: 1,
+                    slug: "parent-slug",
+                    version: 1,
+                    title: "Title A",
+                },
+                {}
+            )
+        ).toEqual({
+            $schema: "004",
+            id: 1,
+            slug: "parent-slug",
+            version: 1,
+            title: "Title A",
+            subtitle: "Parent subtitle",
+        })
     })
 
     it("overwrites values with an empty string if requested", () => {

diff --git a/packages/@ourworldindata/utils/src/grapherConfigUtils.ts b/packages/@ourworldindata/utils/src/grapherConfigUtils.ts
@@ -9,6 +9,7 @@ import {
     omitUndefinedValuesRecursive,
     omitEmptyObjectsRecursive,
     traverseObjects,
+    isEmpty,
 } from "./Util"
 
 const REQUIRED_KEYS = ["$schema", "dimensions"]
@@ -24,20 +25,26 @@ const KEYS_EXCLUDED_FROM_INHERITANCE = [
 export function mergeGrapherConfigs(
     ...grapherConfigs: GrapherInterface[]
 ): GrapherInterface {
+    const configsToMerge = grapherConfigs.filter((c) => !isEmpty(c))
+
+    // return early if there are no configs to merge
+    if (configsToMerge.length === 0) return {}
+    if (configsToMerge.length === 1) return configsToMerge[0]
+
     // warn if one of the configs is missing a schema version
-    const configsWithoutSchema = grapherConfigs.filter(
+    const configsWithoutSchema = configsToMerge.filter(
         (c) => c["$schema"] === undefined
     )
     if (configsWithoutSchema.length > 0) {
-        const ids = configsWithoutSchema.map((c) => c.id)
+        const configsJson = JSON.stringify(configsWithoutSchema, null, 2)
         console.warn(
-            `About to merge Grapher configs with missing schema information. Charts with missing schema information: ${ids}`
+            `About to merge Grapher configs with missing schema information: ${configsJson}`
         )
     }
 
     // abort if the grapher configs have different schema versions
     const uniqueSchemas = uniq(
-        excludeUndefined(grapherConfigs.map((c) => c["$schema"]))
+        excludeUndefined(configsToMerge.map((c) => c["$schema"]))
     )
     if (uniqueSchemas.length > 1) {
         throw new Error(
@@ -48,8 +55,8 @@ export function mergeGrapherConfigs(
     }
 
     // keys that should not be inherited are removed from all but the last config
-    const cleanedConfigs = grapherConfigs.map((config, index) => {
-        if (index === grapherConfigs.length - 1) return config
+    const cleanedConfigs = configsToMerge.map((config, index) => {
+        if (index === configsToMerge.length - 1) return config
         return omit(config, KEYS_EXCLUDED_FROM_INHERITANCE)
     })