build(docs-infra): implement the 'package' API template (#24631)

PR Close #24631

aio/tools/transforms/angular-api-package/processors/processPackages.js

@@ -0,0 +1,63 @@
+const { dirname } = require('canonical-path');
+
+module.exports = function processPackages() {
+  return {
+    $runAfter: ['extractDecoratedClassesProcessor'],
+    $runBefore: ['computing-ids'],
+    $process(docs) {
+      const packageContentFiles = {};
+      const packageMap = {};
+
+      docs = docs.filter(doc => {
+        if (doc.docType === 'package-content') {
+          packageContentFiles[dirname(doc.fileInfo.filePath)] = doc;
+          return false;
+        } else {
+          return true;
+        }
+      });
+
+      docs.forEach(doc => {
+        if (doc.docType === 'module') {
+          // Convert the doc type from "module" to "package"
+          doc.docType = 'package';
+          // The name is actually the full id
+          doc.name = `@angular/${doc.id}`;
+
+          // Partition the exports into groups by type
+          if (doc.exports) {
+            doc.classes = doc.exports.filter(doc => doc.docType === 'class');
+            doc.decorators = doc.exports.filter(doc => doc.docType === 'decorator');
+            doc.functions = doc.exports.filter(doc => doc.docType === 'function');
+            doc.structures = doc.exports.filter(doc => doc.docType === 'enum' || doc.docType === 'interface');
+            doc.directives = doc.exports.filter(doc => doc.docType === 'directive');
+            doc.pipes = doc.exports.filter(doc => doc.docType === 'pipe');
+            doc.types = doc.exports.filter(doc => doc.docType === 'type-alias' || doc.docType === 'const');
+          }
+
+          // Copy over docs from the PACKAGE.md file that is used to document packages
+          const readmeDoc = packageContentFiles[dirname(doc.fileInfo.filePath)];
+          if (readmeDoc) {
+            doc.shortDescription = readmeDoc.shortDescription;
+            doc.description = readmeDoc.description;
+            doc.see = readmeDoc.see;
+            doc.fileInfo = readmeDoc.fileInfo;
+          }
+
+          // Compute the primary/secondary entry point relationships
+          const packageParts = doc.id.split('/');
+          const primaryPackageName = packageParts[0];
+          doc.isPrimaryPackage = packageParts.length === 1;
+          doc.packageInfo = packageMap[primaryPackageName] = packageMap[primaryPackageName] || { primary: undefined, secondary: [] };
+          if (doc.isPrimaryPackage) {
+            doc.packageInfo.primary = doc;
+          } else {
+            doc.packageInfo.secondary.push(doc);
+          }
+        }
+      });
+
+      return docs;
+    }
+  };
+};