feat: provide a property content extractor

Author: alvis

source/property.ts

@@ -0,0 +1,139 @@
+/*
+ *                            *** MIT LICENSE ***
+ * -------------------------------------------------------------------------
+ * This code may be modified and distributed under the MIT license.
+ * See the LICENSE file for details.
+ * -------------------------------------------------------------------------
+ *
+ * @summary   Helpers for property handling
+ *
+ * @author    Alvis HT Tang <alvis@hilbert.space>
+ * @license   MIT
+ * @copyright Copyright (c) 2021 - All Rights Reserved.
+ * -------------------------------------------------------------------------
+ */
+
+import type { FormulaValue, PropertyValue, RollupValue, User } from './types';
+
+type Date = { start: string; end?: string };
+
+type Person = { name: string; avatar?: string };
+
+type NormalisedValue =
+  | undefined
+  | boolean
+  | number
+  | string
+  | string[]
+  | Date
+  | Person
+  | NormalisedValue[];
+
+/* eslint-disable max-lines-per-function */
+/**
+ * extract the content from a property
+ * @param property a property returned from Notion API
+ * @returns its content
+ */
+export function getPropertyContent(property: PropertyValue): NormalisedValue {
+  switch (property.type) {
+    case 'title':
+      return property.title.map((text) => text.plain_text).join('');
+    case 'rich_text':
+      return property.rich_text.map((text) => text.plain_text).join('');
+    case 'number':
+      return property.number;
+    case 'select':
+      return property.select.name;
+    case 'multi_select':
+      return property.multi_select.map((value) => value.name);
+    case 'date':
+      return property.date;
+    case 'people':
+      return property.people.map(getUserContent);
+    case 'files':
+      return property.files.map((file) => file.name);
+    case 'checkbox':
+      return property.checkbox;
+    case 'url':
+      return property.url;
+    case 'email':
+      return property.email;
+    case 'phone_number':
+      return property.phone_number;
+    case 'formula':
+      return getFormulaPropertyContent(property.formula);
+    case 'relation':
+      return undefined;
+    case 'rollup':
+      return getRollupPropertyContent(property.rollup);
+    case 'created_by':
+      return getUserContent(property.created_by);
+    case 'created_time':
+      return property.created_time;
+    case 'last_edited_by':
+      return getUserContent(property.last_edited_by);
+    case 'last_edited_time':
+      return property.last_edited_time;
+    /* istanbul ignore next */
+    default:
+      throw new TypeError(`unknown property`);
+  }
+}
+/* eslint-enable */
+
+/**
+ * extract the content from a formula property
+ * @param formula a formula property returned from Notion API
+ * @returns its content
+ */
+function getFormulaPropertyContent(
+  formula: FormulaValue['formula'],
+): NormalisedValue {
+  switch (formula.type) {
+    case 'string':
+      return formula.string;
+    case 'number':
+      return formula.number;
+    case 'boolean':
+      return formula.boolean;
+    case 'date':
+      return formula.date;
+    /* istanbul ignore next */
+    default:
+      throw new TypeError(`unknown formula property`);
+  }
+}
+
+/**
+ * extract the content from a formula property
+ * @param rollup a formula property returned from Notion API
+ * @returns its content
+ */
+function getRollupPropertyContent(
+  rollup: RollupValue['rollup'],
+): NormalisedValue | NormalisedValue[] {
+  switch (rollup.type) {
+    case 'number':
+      return rollup.number;
+    case 'date':
+      return rollup.date;
+    case 'array':
+      return rollup.array.map(getPropertyContent);
+    /* istanbul ignore next */
+    default:
+      throw new TypeError(`unknown rollup property`);
+  }
+}
+
+/**
+ * extract useful user information
+ * @param user a user property returned from Notion API
+ * @returns its content
+ */
+function getUserContent(user: User): Person {
+  return {
+    name: user.name,
+    avatar: user.avatar_url,
+  };
+}