adopt latest custom build task changes

- single BuildTaskHandler instead of BuildTaskProvider/BuildTaskHandler
  approach
- static build task handler config moved to meta
- default build task properties are now returned as name/value pairs
  using property config
- runWith to declare dependencies across build task handlers, ensuring
  correct dependency graph
- optional getTasks method to implement build task specific constraints

cds-plugin-openapi/index.js

@@ -1,28 +1,18 @@
 /* eslint-disable require-await */
-const path = require("path")
+const cds = require('@sap/cds'), { BuildTaskHandler } = cds.build
-const fs = require("fs")
-const cds = require('@sap/cds'), { BuildTaskProvider, BuildTaskHandler } = cds.build
 const cdsdk = require('@sap/cds-dk')
-const logger = cds.log("build")
 
-// module.exports.activate = () => {
+cds.build.register(class OpenApiHandler extends BuildTaskHandler {
-    cds.build.registerProvider(
+    static get meta() {
-        new (class extends BuildTaskProvider {
+        return {
-            get id() {
+            id: 'openapi',
-                return 'openapi'
+            runWith: ['node-cf', 'java-cf'],
+            config: { src: cds.env.folders.srv.replace(/\/$/, '') }
         }
-            get dependents() {
-                return ['node-cf', 'java-cf']
     }
-            applyDefaults(task) {
-                task.src = task.src || cds.env.folders.srv.replace(/\/$/, '')
-            }
-            get handler() {
-                return class extends BuildTaskHandler {
     async clean() {
-                        fs.rm(path.join(this.task.dest, "openapi-docs"), { recursive: true, force: true }, (err) => err ? logger.error(err) : '')
+        return this.remove('openapi-docs')
     }
-
     async build() {
         const model = await this.model()
         const { options } = this.task
@@ -36,18 +26,4 @@ const logger = cds.log("build")
             this.write(openApi).to(`openapi-docs/${service.name}.openapi3.json`)
         }))
     }
-                }
+})
-            }
-            /**
-             * Additional constraints can be defined, e.g. generate openapi service specification in production builds only.
-             * > cds build --production
-             * > cds build --for node-cf --production 
-             */ 
-            // async lookupTasks() {
-            //     if (process.env.NODE_ENV === 'production') {
-            //         return [{ for: this.id }]
-            //     }
-            // }
-        })()
-    )
-// }