Refactored

lib/runner.js

@@ -72,7 +72,7 @@ const lock = async db => {
   }
 };
 
-const getRunMigrations = async (db, options) => {
+const ensureMigrationsTable = async (db, options) => {
   try {
     const schema = getMigrationTableSchema(options);
     const { migrationsTable } = options;
@@ -99,20 +99,24 @@ const getRunMigrations = async (db, options) => {
         template`CREATE TABLE "${fullTableName}" ( ${idColumn} SERIAL PRIMARY KEY, ${nameColumn} varchar(255) NOT NULL, ${runOnColumn} timestamp NOT NULL)`
       );
     }
-
-    if (!options.noLock) {
-      await lock(db, options);
-    }
-
-    return await db.column(
-      template`SELECT ${nameColumn} FROM "${fullTableName}" ORDER BY ${runOnColumn}, ${idColumn}`,
-      nameColumn
-    );
   } catch (err) {
-    throw new Error(`Unable to fetch migrations: ${err.stack}`);
+    throw new Error(`Unable to ensure migrations table: ${err.stack}`);
   }
 };
 
+const getRunMigrations = async (db, options) => {
+  const schema = getMigrationTableSchema(options);
+  const { migrationsTable } = options;
+  const fullTableName = {
+    schema,
+    name: migrationsTable
+  };
+  return db.column(
+    template`SELECT ${nameColumn} FROM "${fullTableName}" ORDER BY ${runOnColumn}, ${idColumn}`,
+    nameColumn
+  );
+};
+
 const getMigrationsToRun = (options, runNames, migrations) => {
   if (options.direction === "down") {
     const downMigrations = runNames
@@ -150,6 +154,28 @@ const getMigrationsToRun = (options, runNames, migrations) => {
       );
 };
 
+const checkOrder = (runNames, migrations) => {
+  const len = Math.min(runNames.length, migrations.length);
+  for (let i = 0; i < len; i += 1) {
+    const runName = runNames[i];
+    const migrationName = migrations[i].name;
+    if (runName !== migrationName) {
+      throw new Error(
+        `Not run migration ${migrationName} is preceding already run migration ${runName}`
+      );
+    }
+  }
+};
+
+const runMigrations = (toRun, direction) =>
+  toRun.reduce(
+    (promise, migration) =>
+      promise.then(
+        () => (direction === "up" ? migration.applyUp() : migration.applyDown())
+      ),
+    Promise.resolve()
+  );
+
 export default async options => {
   const log = options.log || console.log;
   const db = Db(options.databaseUrl, log);
@@ -165,21 +191,20 @@ export default async options => {
         `CREATE SCHEMA IF NOT EXISTS "${options.migrationsSchema}"`
       );
     }
+
+    await ensureMigrationsTable(db, options);
+
+    if (!options.noLock) {
+      await lock(db, options);
+    }
+
     const [migrations, runNames] = await Promise.all([
       loadMigrationFiles(db, options, log),
       getRunMigrations(db, options)
     ]);
+
     if (options.checkOrder) {
-      const len = Math.min(runNames.length, migrations.length);
-      for (let i = 0; i < len; i += 1) {
-        const runName = runNames[i];
-        const migrationName = migrations[i].name;
-        if (runName !== migrationName) {
-          throw new Error(
-            `Not run migration ${migrationName} is preceding already run migration ${runName}`
-          );
-        }
-      }
+      checkOrder(runNames, migrations);
     }
 
     const toRun = getMigrationsToRun(options, runNames, migrations);
@@ -197,29 +222,16 @@ export default async options => {
 
     if (options.singleTransaction) {
       await db.query("BEGIN");
-    }
-
-    try {
-      await toRun.reduce(
-        (promise, migration) =>
-          promise.then(
-            () =>
-              options.direction === "up"
-                ? migration.applyUp()
-                : migration.applyDown()
-          ),
-        Promise.resolve()
-      );
-
-      if (options.singleTransaction) {
+      try {
+        await runMigrations(toRun, options.direction);
         await db.query("COMMIT");
-      }
-    } catch (err) {
-      if (options.singleTransaction) {
+      } catch (err) {
         log("> Rolling back attempted migration ...");
         await db.query("ROLLBACK");
+        throw err;
       }
-      throw err;
+    } else {
+      await runMigrations(toRun, options.direction);
     }
   } finally {
     db.close();