Add ability to drop tables from a running DynamoDB instance

.gitignore

@@ -1,2 +1,5 @@
 /dynamodb/bin
 /node_modules
+
+# asdf config file
+.tool-versions

README.md

@@ -156,6 +156,11 @@ If seed config is set to true, your configuration will be seeded automatically o
 ]
 ```
 
+##  Dropping tables: sls dynamodb drop
+When running a locally managed DynamoDB instance via sls dynamodb start, your tables go away when you stop the instance. If you use a long running server, like [Local Stack](https://github.com/localstack/localstack), you can use the drop command to drop all the tables that are defined in your `serverless.yml` file as described in the "migrations" section.
+
+Because this is intended to be run manually, there is no configuration for this command.
+
 ## Using DynamoDB Local in your code
 You need to add the following parameters to the AWS NODE SDK dynamodb constructor
 

index.js

@@ -25,6 +25,10 @@ class ServerlessDynamodbLocal {
                         lifecycleEvents: ["migrateHandler"],
                         usage: "Creates local DynamoDB tables from the current Serverless configuration"
                     },
+                    drop: {
+                        lifecycleEvents: ["dropHandler"],
+                        usage: "Drops local DynamoDB tables from the current Serverless configuration",
+                    },
                     seed: {
                         lifecycleEvents: ["seedHandler"],
                         usage: "Seeds local DynamoDB tables with data",
@@ -117,6 +121,7 @@ class ServerlessDynamodbLocal {
 
         this.hooks = {
             "dynamodb:migrate:migrateHandler": this.migrateHandler.bind(this),
+            "dynamodb:drop:dropHandler": this.dropHandler.bind(this),
             "dynamodb:seed:seedHandler": this.seedHandler.bind(this),
             "dynamodb:remove:removeHandler": this.removeHandler.bind(this),
             "dynamodb:install:installHandler": this.installHandler.bind(this),
@@ -197,6 +202,16 @@ class ServerlessDynamodbLocal {
         }
     }
 
+    dropHandler() {
+        if (this.shouldExecute()) {
+            const dynamodb = this.dynamodbOptions();
+            const tables = this.tables;
+            return BbPromise.each(tables, (table) => this.dropTable(dynamodb, table));
+        } else {
+            this.serverlessLog("Skipping drop: DynamoDB Local is not available for stage: " + this.stage);
+        }
+    }
+
     seedHandler() {
         if (this.shouldExecute()) {
             const options = this.options;
@@ -372,5 +387,24 @@ class ServerlessDynamodbLocal {
             });
         });
     }
+
+    dropTable(dynamodb, migration) {
+        return new BbPromise((resolve, reject) => {
+            dynamodb.raw.deleteTable({ TableName: migration.TableName }, (err) => {
+                if (err) {
+                    if (err.name === "ResourceNotFoundException") {
+                        this.serverlessLog(`DynamoDB - Warn - table ${migration.TableName} does not exist`);
+                        resolve();
+                    } else {
+                        this.serverlessLog("DynamoDB - Error - ", err);
+                        reject(err);
+                    }
+                } else {
+                    this.serverlessLog("DynamoDB - dropped table " + migration.TableName);
+                    resolve(migration);
+                }
+            });
+        });
+    }
 }
 module.exports = ServerlessDynamodbLocal;

test/indexTest.js

@@ -102,6 +102,13 @@ describe ("createTable functon",function(){
   });
 });
 
+describe ("dropTable functon",function(){
+  it ("Should check as a function",function(){
+    const tbl = Plugin.prototype.dropTable;
+    assert.equal(typeof tbl, "function");
+  });
+});
+
 describe ("Check the Seeder file",function(){
   it("Table name shoud be a string",function(){
     let tblName = seeder.writeSeeds.name;