feat: support index based filename naming strategy

bin/node-pg-migrate.ts

@@ -173,7 +173,7 @@ const parser = yargs(process.argv.slice(2))
     },
     [migrationFilenameFormatArg]: {
       defaultDescription: '"timestamp"',
-      choices: ['timestamp', 'utc'],
+      choices: ['timestamp', 'utc', 'index'],
       describe:
         'Prefix type of migration filename (Only valid with the create action)',
       type: 'string',
@@ -425,7 +425,8 @@ function readJson(json: unknown): void {
       MIGRATIONS_FILENAME_FORMAT,
       migrationFilenameFormatArg,
       json,
-      (val): val is FilenameFormat => val === 'timestamp' || val === 'utc'
+      (val): val is FilenameFormat =>
+        val === 'timestamp' || val === 'utc' || val === 'index'
     );
     TEMPLATE_FILE_NAME = applyIf(
       TEMPLATE_FILE_NAME,

docs/src/cli.md

@@ -93,7 +93,7 @@ You can adjust defaults by passing arguments to `node-pg-migrate`:
 | `create-migrations-schema`  |         | `false`                         | Create the configured migrations schema if it doesn't exist                                                                                                                                                                                                                             |
 | `migrations-table`          | `t`     | `pgmigrations`                  | The table storing which migrations have been run                                                                                                                                                                                                                                        |
 | `ignore-pattern`            |         | `undefined`                     | Regex pattern for file names to ignore (ignores files starting with `.` by default). Alternatively, provide a [glob](https://www.npmjs.com/package/glob) pattern and set `--use-glob`. Note: enabling glob will read both, `--migrations-dir` _and_ `--ignore-pattern` as glob patterns |
-| `migration-filename-format` |         | `timestamp`                     | Choose prefix of file, `utc` (`20200605075829074`) or `timestamp` (`1591343909074`)                                                                                                                                                                                                     |
+| `migration-filename-format` |         | `timestamp`                     | Choose prefix of file, `utc` (`20200605075829074`), `timestamp` (`1591343909074`), or `index` (`0012`)                                                                                                                                                                                  |
 | `migration-file-language`   | `j`     | `js`                            | Language of the migration file to create (`js`, `ts` or `sql`)                                                                                                                                                                                                                          |
 | `template-file-name`        |         | `undefined`                     | Utilize a custom migration template file with language inferred from its extension. The file should export the up method, accepting a MigrationBuilder instance.                                                                                                                        |
 | `tsconfig`                  |         | `undefined`                     | Path to tsconfig.json. Used to setup transpiling of TS migration files. (Also sets `migration-file-language` to typescript, if not overridden)                                                                                                                                          |

src/migration.ts

@@ -33,6 +33,7 @@ export interface RunMigration {
 export const FilenameFormat = Object.freeze({
   timestamp: 'timestamp',
   utc: 'utc',
+  index: 'index',
 });
 
 export type FilenameFormat =
@@ -49,6 +50,7 @@ export interface CreateOptionsDefault {
 
 export type CreateOptions = {
   filenameFormat?: FilenameFormat;
+  ignorePattern?: string;
 } & (CreateOptionsTemplate | CreateOptionsDefault);
 
 const SEPARATOR = '_';
@@ -187,8 +189,11 @@ async function getLastSuffix(
 }
 
 /**
- * extracts numeric value from everything in `filename` before `SEPARATOR`.
- * 17 digit numbers are interpreted as utc date and converted to the number representation of that date.
+ * Extracts numeric value from everything in `filename` before `SEPARATOR`.
+ * 17 digit numbers are interpreted as UTC date and converted to the number
+ * representation of that date. 1...4 digit numbers are interpreted as index
+ * based naming scheme.
+ *
  * @param filename filename to extract the prefix from
  * @param logger Redirect messages to this logger object, rather than `console`.
  * @returns numeric value of the filename prefix (everything before `SEPARATOR`).
@@ -219,7 +224,11 @@ export function getNumericPrefix(
     }
   }
 
-  logger.error(`Can't determine timestamp for ${prefix}`);
+  if (prefix && /^\d{1,4$/) {
+    return Number(prefix);
+  }
+
+  logger.error(`Cannot determine numeric prefix for ${prefix}`);
   return Number(prefix) || 0;
 }
 
@@ -232,22 +241,69 @@ async function resolveSuffix(
 }
 
 export class Migration implements RunMigration {
-  // class method that creates a new migration file by cloning the migration template
+  /**
+   * Get file prefix for a new migrations file
+   *
+   * @method Migration.getFilePrefix
+   * @param filenameFormat Filename format
+   * @param directory Migrations directory
+   * @param [ignorePattern] Glob ignore pattern
+   * @returns string New file prefix
+   */
+  static async getFilePrefix(
+    filenameFormat: string,
+    directory: string,
+    ignorePattern?: string
+  ): Promise<string> {
+    if (filenameFormat === FilenameFormat.index) {
+      const filePaths = await getMigrationFilePaths(directory, {
+        ignorePattern,
+        useGlob: /\*/.test(directory) || /\*/.test(ignorePattern || ''),
+      });
+
+      // Get the minimum last found prefix as the total number of matching files
+      let lastPrefix = filePaths.length;
+
+      // Index can be used only when there are no mismatching filenames, so all
+      // the filenames have to be verified first against "index" naming pattern
+      for (const filenamePath of filePaths) {
+        const filename = basename(filenamePath);
+        if (!/^\d{1,4}\D/.test(filename)) {
+          throw new Error(
+            `Cannot deduce index for previously created file "${filenamePath}"`
+          );
+        }
+
+        lastPrefix = Math.max(lastPrefix, getNumericPrefix(filename));
+      }
+
+      // Next prefix is one more than the last found prefix
+      return `${lastPrefix + 1}`.padStart(4, '0');
+    }
+
+    return filenameFormat === FilenameFormat.utc
+      ? new Date().toISOString().replace(/\D/g, '')
+      : Date.now().toString();
+  }
+
+  // Class method that creates a new migration file by cloning the migration template
   static async create(
     name: string,
     directory: string,
     options: CreateOptions = {}
   ): Promise<string> {
-    const { filenameFormat = FilenameFormat.timestamp } = options;
+    const { filenameFormat = FilenameFormat.timestamp, ignorePattern } =
+      options;
 
-    // ensure the migrations directory exists
+    // Ensure the migrations directory exists
     await mkdir(directory, { recursive: true });
 
-    const now = new Date();
-    const time =
-      filenameFormat === FilenameFormat.utc
-        ? now.toISOString().replace(/\D/g, '')
-        : now.valueOf();
+    // Get prefix based on the configured naming scheme
+    const prefix = await Migration.getFilePrefix(
+      filenameFormat,
+      directory,
+      ignorePattern
+    );
 
     const templateFileName =
       'templateFileName' in options
@@ -262,7 +318,7 @@ export class Migration implements RunMigration {
     const suffix = getSuffixFromFileName(templateFileName);
 
     // file name looks like migrations/1391877300255_migration-title.js
-    const newFile = join(directory, `${time}${SEPARATOR}${name}.${suffix}`);
+    const newFile = join(directory, `${prefix}${SEPARATOR}${name}.${suffix}`);
 
     // copy the default migration template to the new file location
     await new Promise<void>((resolve, reject) => {

test/migration.spec.ts

@@ -5,6 +5,7 @@ import type { RunnerOption } from '../src';
 import type { DBConnection } from '../src/db';
 import type { Logger } from '../src/logger';
 import {
+  FilenameFormat,
   getMigrationFilePaths,
   getNumericPrefix,
   Migration,
@@ -53,6 +54,11 @@ describe('migration', () => {
         getNumericPrefix(now.toISOString().replace(/\D/g, ''), logger)
       ).toBe(now.valueOf());
     });
+
+    it('should get prefix for index strings', () => {
+      expect(getNumericPrefix('0001', logger)).toBe(1);
+      expect(getNumericPrefix('1234', logger)).toBe(1234);
+    });
   });
 
   describe('getMigrationFilePaths', () => {
@@ -126,6 +132,21 @@ describe('migration', () => {
         expect(isAbsolute(filePath)).toBeTruthy();
       }
     });
+
+    it('should resolve the next index for file paths', async () => {
+      const dir = 'test/{cockroach,migrations}/**';
+      // ignores those files that have `test` in their name (not in the path, just filename)
+      const ignorePattern = '*/cockroach/*test*';
+
+      const nextPrefix = await Migration.getFilePrefix(
+        FilenameFormat.index,
+        dir,
+        ignorePattern
+      );
+
+      // There are 106 files matching the pattern
+      expect(nextPrefix).toEqual('0107');
+    });
   });
 
   describe('self.applyUp', () => {