Add method to patch services

packages/backend/src/services/Container.js

@@ -32,6 +32,11 @@ class Container {
             ? cls.getInstance({ services: this, config, my_config, name, args })
             : new cls({ services: this, config, my_config, name, args }) ;
     }
+    patchService (name, patch, args) {
+        const original_service = this.instances_[name];
+        const patch_instance = new patch();
+        patch_instance.patch({ original_service, args });
+    }
     set (name, instance) { this.instances_[name] = instance; }
     get (name, opts) {
         if ( this.instances_[name] ) {

packages/backend/src/services/ServicePatch.js

@@ -0,0 +1,27 @@
+const { AdvancedBase } = require("@heyputer/puter-js-common");
+
+class ServicePatch extends AdvancedBase {
+    patch ({ original_service }) {
+        const patch_methods = this._get_merged_static_object('PATCH_METHODS');
+        for ( const k in patch_methods ) {
+            if ( typeof patch_methods[k] !== 'function' ) {
+                throw new Error(`Patch method ${k} to ${original_service.service_name} ` +
+                    `from ${this.constructor.name} ` +
+                    `is not a function.`)
+            }
+
+            const patch_method = patch_methods[k];
+
+            const patch_arguments = {
+                that: original_service,
+                original: original_service[k].bind(original_service),
+            };
+
+            original_service[k] = (...a) => {
+                return patch_method.call(this, patch_arguments, ...a);
+            }
+        }
+    }
+}
+
+module.exports = ServicePatch;