feat: adapt build plugin implementation to new API (#319)

Co-authored-by: Lothar Bender <lothar.bender@sap.com>

postgres/cds-plugin.js

@@ -1,9 +1,11 @@
-const cds = require('@sap/cds/lib')
+const cds = require('@sap/cds')
 
 if (!cds.env.fiori.lean_draft) {
   throw new Error('"@cap-js/postgres" only works if cds.fiori.lean_draft is enabled. Please adapt your configuration.')
 }
 
-if (cds.cli.command === 'build') {
-  module.exports = require('./lib/build')
-}
+// requires @sap/cds-dk version >= 7.3.2
+cds.build?.register?.('postgres', {
+  impl: '@cap-js/postgres/lib/build.js',
+  taskDefaults: { src: cds.env.folders.db }
+})

postgres/lib/build.js

@@ -1,44 +1,22 @@
 const cds = require('@sap/cds')
+const { fs, path } = cds.utils
 
-let BuildPlugin
-try {
-  ({ BuildPlugin } = require('@sap/cds-dk/lib/build'))
-} catch (e) {
-  if (e.code === 'ENOTFOUND') throw `No build plugin mechanism for @sap/cds-dk found. Please install @sap/cds-dk for development using 'npm i -D @sap/cds-dk@^7.3.0'`
-  else throw e
-}
-
-const { fs, path, rimraf } = cds.utils
+module.exports = class PostgresBuildPlugin extends cds.build.BuildPlugin {
 
-module.exports = class PostgresBuildPlugin extends BuildPlugin {
-  static hasTask() { // REVISIT: should be unnecessary -> plugin mechanism knows what to pull
-    return cds.requires.db.kind === 'postgres'
-  }
-
-  static getTaskDefaults() {
-    return { src: cds.env.folders.db }
-  }
-
-  init() {
-    this.task.dest = cds.env.build.target === '.' ? path.join('gen','pg') : path.join('gen', 'pg')
-  }
-
-  async clean() {
-    await rimraf(this.task.dest)
+  static hasTask() {
+    return cds.requires.db?.kind === 'postgres'
   }
 
   async build() {
     const model = await this.model()
-    if (!model) {
-      return
-    }
+    if (!model) return
 
     const promises = []
     promises.push(this.write({
         dependencies: { '@sap/cds': '^7', '@cap-js/postgres': '^1' },
         scripts: { start: 'cds-deploy' },
-      }).to('package.json'))
-    promises.push(this.write(cds.compile.to.json(model)).to(path.join('db', 'csn.json')))
+      }).to('pg/package.json'))
+    promises.push(this.write(cds.compile.to.json(model)).to(path.join('pg/db', 'csn.json')))
 
     let data
     if (fs.existsSync(path.join(this.task.src, 'data'))) {
@@ -47,7 +25,7 @@ module.exports = class PostgresBuildPlugin extends BuildPlugin {
       data = 'csv'
     }
     if (data) {
-      promises.push(this.copy(data).to(path.join('db', 'data')))
+      promises.push(this.copy(data).to(path.join('pg/db', 'data')))
     }
     return Promise.all(promises)
   }