Add import readMigrations function in the Database class

jest.config.js

@@ -9,7 +9,8 @@ module.exports = {
   testPathIgnorePatterns: [
     '/build',
     '/node_modules/',
-    '/vendor-typings'
+    '/vendor-typings',
+    '__tests__/data'
   ],
   coverageThreshold: {
     global: {

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sqlite",
-  "version": "5.1.1",
+  "version": "5.1.2",
   "description": "SQLite client for Node.js applications with SQL-based migrations API written in Typescript",
   "main": "build/index.js",
   "types": "build/index.d.ts",

src/Database.ts

@@ -2,7 +2,7 @@ import * as sqlite3 from 'sqlite3'
 import { ISqlite, IMigrate } from './interfaces'
 
 import { Statement } from './Statement'
-import { migrate } from './utils/migrate'
+import { migrate, readMigrations } from './utils/migrate'
 import { toSqlParams } from './utils/strings'
 
 import MigrationParams = IMigrate.MigrationParams
@@ -365,6 +365,15 @@ export class Database<
     await migrate(this, config)
   }
 
+  /**
+   * Performs a database migration read operation.
+   * @returns List of objects with name, id of migrations and SQL code for up and down migration
+   * You can run up and down with `db.exec(migrations[0].up)` or `db.exec(migrations[0].down)`. Or with other commands that can run SQL code.
+   */
+  readMigrations (migrationPath?: string): Promise<IMigrate.MigrationData[]> {
+    return readMigrations(migrationPath)
+  }
+
   /**
    * The methods underneath requires creative work to implement. PRs / proposals accepted!
    */

src/__tests__/data/migrations.data.ts

@@ -0,0 +1,45 @@
+export const initial001 = {
+  up: `CREATE TABLE Category (
+  id   INTEGER PRIMARY KEY,
+  name TEXT    NOT NULL
+);
+
+CREATE TABLE Post (
+  id          INTEGER PRIMARY KEY,
+  categoryId  INTEGER NOT NULL,
+  title       TEXT    NOT NULL,
+  isPublished NUMERIC NOT NULL DEFAULT 0,
+  CONSTRAINT Post_fk_categoryId FOREIGN KEY (categoryId)
+    REFERENCES Category (id) ON UPDATE CASCADE ON DELETE CASCADE,
+  CONSTRAINT Post_ck_isPublished CHECK (isPublished IN (0, 1))
+);
+
+CREATE INDEX Post_ix_categoryId ON Post (categoryId);
+
+INSERT INTO Category (id, name) VALUES (1, 'Test');`,
+  down: `DROP INDEX Post_ix_categoryId;
+DROP TABLE Post;
+DROP TABLE Category;`
+}
+
+export const someFeature002 = {
+  up: `CREATE TABLE Test (
+  id   INTEGER PRIMARY KEY,
+  name TEXT    NOT NULL
+);`,
+  down: `DROP TABLE Test;`
+}
+
+export const testCert003 = {
+  up: `CREATE TABLE whatever ( certificate TEXT );
+INSERT INTO whatever ( certificate ) VALUES (
+  '-----BEGIN CERTIFICATE-----
+some contents
+-----END CERTIFICATE-----');`,
+  down: `DROP TABLE whatever;`
+}
+
+export const noDown004 = {
+  up: `CREATE TABLE IF NOT EXISTS downless ( value TEXT );
+INSERT INTO downless ( value ) VALUES ('down migration is optional');`
+}

src/__tests__/index.test.ts

@@ -4,6 +4,13 @@
 import { open } from '..'
 import * as sqlite3 from 'sqlite3'
 
+import {
+  initial001,
+  noDown004,
+  someFeature002,
+  testCert003
+} from './data/migrations.data'
+
 describe('index', () => {
   // enable the sqlite cached database or not
   const driver = [
@@ -40,6 +47,41 @@ describe('index', () => {
     })
   })
 
+  driver.forEach(c => {
+    it(`should return list of migrations with name, id, down and up variables, cached = ${
+      c.cached
+    }`, async () => {
+      // const expectedData =
+      const db = await open({
+        filename: ':memory:',
+        driver: c.driver
+      })
+
+      await db.migrate()
+
+      const migrations = await db.readMigrations()
+
+      expect(migrations).toEqual([
+        { id: 1, name: 'initial', up: initial001.up, down: initial001.down },
+        {
+          id: 2,
+          name: 'some-feature',
+          up: someFeature002.up,
+          down: someFeature002.down
+        },
+        {
+          id: 3,
+          name: 'test-cert',
+          up: testCert003.up,
+          down: testCert003.down
+        },
+        { id: 4, name: 'no-down', up: noDown004.up, down: '' }
+      ])
+
+      await db.close()
+    })
+  })
+
   /* disabled since sqlite3-offline-next hasn't been maintained in two years
   and there are no recent builds compatible with newer versions of node
   it('should allow an anonymous database', async () => {

src/utils/migrate.ts

@@ -49,8 +49,11 @@ export async function readMigrations (migrationPath?: string) {
               return reject(err)
             }
 
-            const [up, down] = data.split(/^--\s+?down\b/im)
+            const [up, down] = data
+              .split(/^--\s+?down\b/im)
+              .map(value => value.replace(/^-{3,}$/gim, '').trim())
 
+            delete migration.filename
             const migrationData = migration as Partial<MigrationData>
             migrationData.up = up.replace(/^-- .*?$/gm, '').trim() // Remove comments
             migrationData.down = down ? down.trim() : '' // and trim whitespaces