Add expo-sqlite, the ability to test it, and a promisifying wrapper

.flowconfig

@@ -115,6 +115,9 @@ munge_underscores=true
 
 module.name_mapper='^react-native/\(.*\)$' -> '<PROJECT_ROOT>/node_modules/react-native/\1'
 module.name_mapper='^@?[./a-zA-Z0-9$_-]+\.\(bmp\|gif\|jpg\|jpeg\|png\|psd\|svg\|webp\|m4v\|mov\|mp4\|mpeg\|mpg\|webm\|aac\|aiff\|caf\|m4a\|mp3\|wav\|html\|pdf\)$' -> '<PROJECT_ROOT>/node_modules/react-native/Libraries/Image/RelativeImageStub'
+# This lets us write .js.flow files instead of libdefs.
+# Add more libraries as needed to this pattern with `\|`: `foo\|bar\|…`.
+module.name_mapper='^\(sqlite3\)$' -> '<PROJECT_ROOT>/types/\0'
 
 suppress_type=$FlowIssue
 suppress_type=$FlowFixMe

android/app/src/main/java/com/zulipmobile/generated/BasePackageList.java

@@ -12,6 +12,7 @@ public List<Package> getPackageList() {
         new expo.modules.filesystem.FileSystemPackage(),
         new expo.modules.imageloader.ImageLoaderPackage(),
         new expo.modules.screenorientation.ScreenOrientationPackage(),
+        new expo.modules.sqlite.SQLitePackage(),
         new expo.modules.webbrowser.WebBrowserPackage()
     );
   }

docs/howto/libdefs.md

@@ -17,6 +17,39 @@ dependencies well-typed.
 
 -----
 
+## Normal type definitions (`.js.flow`): `sqlite3`
+
+This library doesn't have its own Flow types, and doesn't have its own
+TypeScript types so it's not suited for Flowgen.  We wrote type
+definitions from scratch.
+
+For doing that, an option that's much more convenient than a libdef in
+`flow-typed` is to write a `.js.flow` file.  In particular iterating
+on changes is much faster and easier, because Flow does its usual
+incremental thing; whereas with a libdef it restarts from scratch on
+each edit.
+
+The major difference in structure between a libdef and a `.js.flow`
+file is that the latter doesn't have `declare module` blocks.
+Instead the whole file describes one module, identified by where it is
+in the filesystem -- just like a normal JS file does.  The contents of
+the file are very much like the body of any given `declare module`
+block in a libdef: `export type Foo = …` and `declare export class
+Bar { … }` and so on.
+
+In order to be able to write a `.js.flow` file for the library in our
+tree (rather than under `node_modules/`) and have Flow find it, we
+added the following line to `.flowconfig`:
+
+    module.name_mapper='^\(sqlite3\)$' -> '<PROJECT_ROOT>/types/\0'
+
+Then the file goes at `types/sqlite3.js.flow`.
+
+The actual contents of the `.js.flow` file were based on the library's
+API documentation, and consulting its implementation for points where
+the documentation wasn't clear.
+
+
 ## `remotedev-serialize`
 
 Some assembly was required for a libdef for `remotedev-serialize`, but

flow-typed/expo-sqlite_vx.x.x.js

@@ -0,0 +1,199 @@
+// `flowgen --no-inexact --interface-records node_modules/expo-sqlite/build/SQLite.types.d.ts`
+// from expo-sqlite 10.0.3
+// with s/export type/declare export type/g, and as noted with "Zulip fix" below
+declare module 'expo-sqlite/build/SQLite.types' {
+  /**
+   * Flowtype definitions for SQLite.types
+   * Generated by Flowgen from a Typescript Definition
+   * Flowgen v1.14.1
+   */
+
+   declare export type Window = {|
+    openDatabase?: (
+      name: string,
+      version: string,
+      displayName: string,
+      estimatedSize: number,
+      creationCallback?: DatabaseCallback
+    ) => Database,
+  |};
+  declare export type DatabaseCallback = (database: Database) => void;
+  /**
+   * `Database` objects are returned by calls to `SQLite.openDatabase()`. Such an object represents a
+   * connection to a database on your device.
+   */
+  declare export type Database = {|
+    version: string,
+
+    /**
+     * Execute a database transaction.
+     * @param callback A function representing the transaction to perform. Takes a Transaction
+     * (see below) as its only parameter, on which it can add SQL statements to execute.
+     * @param errorCallback Called if an error occurred processing this transaction. Takes a single
+     * parameter describing the error.
+     * @param successCallback Called when the transaction has completed executing on the database.
+     */
+    transaction(
+      callback: SQLTransactionCallback,
+      errorCallback?: SQLTransactionErrorCallback,
+      successCallback?: () => void
+    ): void,
+    readTransaction(
+      callback: SQLTransactionCallback,
+      errorCallback?: SQLTransactionErrorCallback,
+      successCallback?: () => void
+    ): void,
+  |};
+  declare export type SQLTransactionCallback = (transaction: SQLTransaction) => void;
+  declare export type SQLTransactionErrorCallback = (error: SQLError) => void;
+  /**
+   * A `SQLTransaction` object is passed in as a parameter to the `callback` parameter for the
+   * `db.transaction()` method on a `Database` (see above). It allows enqueuing SQL statements to
+   * perform in a database transaction.
+   */
+  declare export type SQLTransaction = {|
+    /**
+     * Enqueue a SQL statement to execute in the transaction. Authors are strongly recommended to make
+     * use of the `?` placeholder feature of the method to avoid against SQL injection attacks, and to
+     * never construct SQL statements on the fly.
+     * @param sqlStatement A string containing a database query to execute expressed as SQL. The string
+     * may contain `?` placeholders, with values to be substituted listed in the `arguments` parameter.
+     * @param args An array of values (numbers or strings) to substitute for `?` placeholders in the
+     * SQL statement.
+     * @param callback Called when the query is successfully completed during the transaction. Takes
+     * two parameters: the transaction itself, and a `ResultSet` object (see below) with the results
+     * of the query.
+     * @param errorCallback Called if an error occurred executing this particular query in the
+     * transaction. Takes two parameters: the transaction itself, and the error object.
+     */
+    executeSql(
+      sqlStatement: string,
+      args?: $ReadOnlyArray<number | string>, // Zulip fix
+      callback?: SQLStatementCallback,
+      errorCallback?: SQLStatementErrorCallback
+    ): void,
+  |};
+  declare export type SQLStatementCallback = (
+    transaction: SQLTransaction,
+    resultSet: SQLResultSet
+  ) => void;
+  declare export type SQLStatementErrorCallback = (
+    transaction: SQLTransaction,
+    error: SQLError
+  ) => boolean;
+  declare export type SQLResultSet = {|
+    /**
+     * The row ID of the row that the SQL statement inserted into the database, if a row was inserted.
+     */
+    insertId?: number,
+
+    /**
+     * The number of rows that were changed by the SQL statement.
+     */
+    rowsAffected: number,
+    rows: SQLResultSetRowList,
+  |};
+  declare export type SQLResultSetRowList = {|
+    /**
+     * The number of rows returned by the query.
+     */
+    length: number,
+
+    /**
+     * Returns the row with the given `index`. If there is no such row, returns `null`.
+     * @param index Index of row to get.
+     */
+    item(index: number): any,
+
+    /**
+     * The actual array of rows returned by the query. Can be used directly instead of
+     * getting rows through rows.item().
+     */
+    _array: any[],
+  |};
+  declare export class SQLError {
+    static UNKNOWN_ERR: number;
+    static DATABASE_ERR: number;
+    static VERSION_ERR: number;
+    static TOO_LARGE_ERR: number;
+    static QUOTA_ERR: number;
+    static SYNTAX_ERR: number;
+    static CONSTRAINT_ERR: number;
+    static TIMEOUT_ERR: number;
+    code: number;
+    message: string;
+  }
+  declare export type WebSQLDatabase = {|
+    ...$Exact<Database>,
+
+    exec(queries: Query[], readOnly: boolean, callback: SQLiteCallback): void,
+  |};
+  declare export type Query = {|
+    sql: string,
+    args: mixed[],
+  |};
+  declare export type ResultSetError = {|
+    error: Error,
+  |};
+  /**
+   * `ResultSet` objects are returned through second parameter of the `success` callback for the
+   * `tx.executeSql()` method on a `SQLTransaction` (see above).
+   */
+  declare export type ResultSet = {|
+    /**
+     * The row ID of the row that the SQL statement inserted into the database, if a row was inserted.
+     */
+    insertId?: number,
+
+    /**
+     * The number of rows that were changed by the SQL statement.
+     */
+    rowsAffected: number,
+    rows: {|
+      [column: string]: any,
+    |}[],
+  |};
+  declare export type SQLiteCallback = (
+    error?: Error | null,
+    resultSet?: (ResultSetError | ResultSet)[]
+  ) => void;
+}
+
+// `flowgen --no-inexact --interface-records node_modules/expo-sqlite/build/SQLite.d.ts`
+// from expo-sqlite 10.0.3
+// with imports fixed up
+declare module 'expo-sqlite/build/SQLite' {
+  /**
+   * Flowtype definitions for SQLite
+   * Generated by Flowgen from a Typescript Definition
+   * Flowgen v1.14.1
+   */
+
+  import type { WebSQLDatabase } from "expo-sqlite/build/SQLite.types";
+
+  /**
+   * Open a database, creating it if it doesn't exist, and return a `Database` object. On disk,
+   * the database will be created under the app's [documents directory](../filesystem), i.e.
+   * `${FileSystem.documentDirectory}/SQLite/${name}`.
+   * > The `version`, `description` and `size` arguments are ignored, but are accepted by the function
+   * for compatibility with the WebSQL specification.
+   * @param name Name of the database file to open.
+   * @param version
+   * @param description
+   * @param size
+   * @param callback
+   * @return
+   */
+  declare export function openDatabase(
+    name: string,
+    version?: string,
+    description?: string,
+    size?: number,
+    callback?: (db: WebSQLDatabase) => void
+  ): WebSQLDatabase;
+}
+
+declare module 'expo-sqlite' {
+  declare export * from 'expo-sqlite/build/SQLite';
+  declare export * from 'expo-sqlite/build/SQLite.types';
+}

ios/Podfile.lock

@@ -28,6 +28,9 @@ PODS:
   - EXScreenOrientation (3.3.0):
     - React-Core
     - UMCore
+  - EXSQLite (9.2.1):
+    - ExpoModulesCore
+    - UMCore
   - EXWebBrowser (9.2.0):
     - UMCore
   - FBLazyVector (0.64.3)
@@ -430,6 +433,7 @@ DEPENDENCIES:
   - EXImageLoader (from `../node_modules/expo-image-loader/ios`)
   - ExpoModulesCore (from `../node_modules/expo-modules-core/ios`)
   - EXScreenOrientation (from `../node_modules/expo-screen-orientation/ios`)
+  - EXSQLite (from `../node_modules/expo-sqlite/ios`)
   - EXWebBrowser (from `../node_modules/expo-web-browser/ios`)
   - FBLazyVector (from `../node_modules/react-native/Libraries/FBLazyVector`)
   - FBReactNativeSpec (from `../node_modules/react-native/React/FBReactNativeSpec`)
@@ -534,6 +538,8 @@ EXTERNAL SOURCES:
     :path: "../node_modules/expo-modules-core/ios"
   EXScreenOrientation:
     :path: "../node_modules/expo-screen-orientation/ios"
+  EXSQLite:
+    :path: "../node_modules/expo-sqlite/ios"
   EXWebBrowser:
     :path: "../node_modules/expo-web-browser/ios"
   FBLazyVector:
@@ -642,6 +648,7 @@ SPEC CHECKSUMS:
   EXImageLoader: d3531a3fe530b22925c19977cb53bb43e3821fe6
   ExpoModulesCore: 2734852616127a6c1fc23012197890a6f3763dc7
   EXScreenOrientation: 09fe6b6b87899ae0c9320255bda7b7513cdfc8ec
+  EXSQLite: cddb3b3f4c6999761c157b88dc8b55c7af2cd86b
   EXWebBrowser: 76783ba5dcb8699237746ecf41a9643d428a4cc5
   FBLazyVector: c71c5917ec0ad2de41d5d06a5855f6d5eda06971
   FBReactNativeSpec: ddd61666683147c613f5c89e2ce4e6c5e4f90d63

jest.config.js

@@ -5,6 +5,7 @@
 const transformModulesWhitelist = [
   'expo-apple-authentication',
   'expo-application',
+  'expo-sqlite',
   'expo-web-browser',
   'react-native',
   '@react-native',

jest/jestSetup.js

@@ -67,6 +67,10 @@ jest.mock('react-native', () => {
   return ReactNative;
 });
 
+jest.mock('immediate', () => require('./mock-immediate').default);
+
+jest.mock('expo-sqlite', () => require('./mock-expo-sqlite'));
+
 /**
  * Boring mocks
  *