Merge pull request #889 from jan-molak/features/to-json

feat(object): toJSON available as a standalone function

Author: jan-molak

.github/workflows/main.yaml

@@ -14,7 +14,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [ 16.x, 18.x, 20.x ]
+        node-version: [ 16.x, 18.x, 20.x, 22.x ]
 
     steps:
       - uses: actions/checkout@v4

package.json

@@ -38,8 +38,7 @@
   },
   "homepage": "https://jan-molak.github.io/tiny-types/",
   "engines": {
-    "node": "^16 || ^18 || ^20",
-    "npm": "^8 || ^9 || ^10"
+    "node": "^16 || ^18 || ^20 || ^22"
   },
   "devDependencies": {
     "@types/chai": "4.3.17",

src/TinyType.ts

@@ -1,7 +1,7 @@
 import { ensure } from './ensure';
-import { equal, isRecord, significantFieldsOf, stringify } from './objects';
+import { equal, significantFieldsOf, stringify, toJSON } from './objects';
 import { isDefined } from './predicates';
-import { JSONObject, JSONValue, Serialisable } from './types';
+import { JSONValue, Serialisable } from './types';
 
 /**
  * @desc The {@link TinyTypeOf} can be used to define simple
@@ -137,68 +137,3 @@ export abstract class TinyType implements Serialisable {
         }, {}) as JSONValue;
     }
 }
-
-function toJSON(value: any): JSONValue | undefined {
-    switch (true) {
-        case value && !! value.toJSON:
-            return value.toJSON();
-        case value && Array.isArray(value):
-            return value.map(v => {
-                return v === undefined
-                    ? null
-                    : toJSON(v) as JSONValue;
-            });
-        case value && value instanceof Map:
-            return mapToJSON(value);
-        case value && value instanceof Set:
-            return toJSON(Array.from(value));
-        case value && isRecord(value):
-            return recordToJSON(value);
-        case value && value instanceof Error:
-            return errorToJSON(value);
-        case isSerialisablePrimitive(value):
-            return value;
-        default:
-            return JSON.stringify(value);
-    }
-}
-
-function mapToJSON(map: Map<any, any>): JSONObject {
-    const serialised = Array.from(map, ([key, value]) => [ toJSON(key), toJSON(value) ]);
-
-    return Object.fromEntries(serialised);
-}
-
-function recordToJSON(value: Record<any, any>): JSONObject {
-    const serialised = Object.entries(value)
-        .map(([ k, v ]) => [ toJSON(k), toJSON(v) ]);
-
-    return Object.fromEntries(serialised);
-}
-
-function errorToJSON(value: Error): JSONObject {
-    return Object.getOwnPropertyNames(value)
-        .reduce((serialised, key) => {
-            serialised[key] = toJSON(value[key])
-            return serialised;
-        }, { }) as JSONObject;
-}
-
-function isSerialisableNumber(value: unknown): value is number {
-    return typeof value === 'number'
-        && ! Number.isNaN(value)
-        && value !== Number.NEGATIVE_INFINITY
-        && value !== Number.POSITIVE_INFINITY;
-}
-
-function isSerialisablePrimitive(value: unknown): value is string | boolean | number | null | undefined {
-    if (['string', 'boolean'].includes(typeof value)) {
-        return true;
-    }
-
-    if (value === null || value === undefined) {
-        return true;
-    }
-
-    return isSerialisableNumber(value);
-}

src/objects/index.ts

@@ -4,3 +4,4 @@ export * from './isObject';
 export * from './isRecord';
 export * from './significantFields';
 export * from './stringify';
+export * from './toJSON';

src/objects/toJSON.ts

@@ -0,0 +1,73 @@
+/* eslint-disable unicorn/filename-case */
+import { JSONObject, JSONValue } from '../types';
+import { isRecord } from './isRecord';
+
+/**
+ * Serialises the object to a JSON representation.
+ *
+ * @param value
+ */
+export function toJSON(value: any): JSONValue | undefined { // eslint-disable-line @typescript-eslint/explicit-module-boundary-types
+    switch (true) {
+        case value && !! value.toJSON:
+            return value.toJSON();
+        case value && Array.isArray(value):
+            return value.map(v => {
+                return v === undefined
+                    ? null
+                    : toJSON(v) as JSONValue;
+            });
+        case value && value instanceof Map:
+            return mapToJSON(value);
+        case value && value instanceof Set:
+            return toJSON(Array.from(value));
+        case value && isRecord(value):
+            return recordToJSON(value);
+        case value && value instanceof Error:
+            return errorToJSON(value);
+        case isSerialisablePrimitive(value):
+            return value;
+        default:
+            return JSON.stringify(value);
+    }
+}
+
+function mapToJSON(map: Map<any, any>): JSONObject {
+    const serialised = Array.from(map, ([key, value]) => [ toJSON(key), toJSON(value) ]);
+
+    return Object.fromEntries(serialised);
+}
+
+function recordToJSON(value: Record<any, any>): JSONObject {
+    const serialised = Object.entries(value)
+        .map(([ k, v ]) => [ toJSON(k), toJSON(v) ]);
+
+    return Object.fromEntries(serialised);
+}
+
+function errorToJSON(value: Error): JSONObject {
+    return Object.getOwnPropertyNames(value)
+        .reduce((serialised, key) => {
+            serialised[key] = toJSON(value[key])
+            return serialised;
+        }, { }) as JSONObject;
+}
+
+function isSerialisableNumber(value: unknown): value is number {
+    return typeof value === 'number'
+        && ! Number.isNaN(value)
+        && value !== Number.NEGATIVE_INFINITY
+        && value !== Number.POSITIVE_INFINITY;
+}
+
+function isSerialisablePrimitive(value: unknown): value is string | boolean | number | null | undefined {
+    if (['string', 'boolean'].includes(typeof value)) {
+        return true;
+    }
+
+    if (value === null || value === undefined) {
+        return true;
+    }
+
+    return isSerialisableNumber(value);
+}