Feat/add test and add better support for validation

src/queryKinds/ddl/table/Alter.test.ts

@@ -0,0 +1,50 @@
+import { describe, expect, it } from "vitest";
+import AlterTableQuery from "./Alter.js";
+import Column from "../../../queryUtils/Column.js";
+
+
+describe('Alter Table Query', () => {
+  it('should create a basic ALTER TABLE query to add a column', () => {
+    const query = new AlterTableQuery('users')
+      .addColumnsToAdd(Column('id', 'INT').primaryKey().notNull())
+      .build();
+
+    expect(query).toEqual([
+      'ALTER TABLE "users" ADD COLUMN id INT;',
+      'ALTER TABLE "users" ALTER COLUMN id SET NOT NULL;',
+      'ALTER TABLE "users" ADD CONSTRAINT id_pkey PRIMARY KEY (id);',
+    ]);
+  });
+
+  it('should allow to set table name later', () => {
+    const query = new AlterTableQuery()
+      .table('products')
+      .addColumnsToAdd([
+        Column('product_id', 'INT').primaryKey().notNull(),
+      ])
+      .build();
+
+    expect(query).toEqual([
+      'ALTER TABLE "products" ADD COLUMN product_id INT;',
+      'ALTER TABLE "products" ALTER COLUMN product_id SET NOT NULL;',
+      'ALTER TABLE "products" ADD CONSTRAINT product_id_pkey PRIMARY KEY (product_id);',
+    ]);
+  });
+
+  it('should allow to set columns to add', () => {
+    const query = new AlterTableQuery('orders')
+      .setColumnsToAdd([
+        Column('order_id', 'INT').primaryKey().notNull(),
+        Column('order_date', 'DATE').notNull(),
+      ])
+      .build();
+
+    expect(query).toEqual([
+      'ALTER TABLE "orders" ADD COLUMN order_id INT;',
+      'ALTER TABLE "orders" ALTER COLUMN order_id SET NOT NULL;',
+      'ALTER TABLE "orders" ADD CONSTRAINT order_id_pkey PRIMARY KEY (order_id);',
+      'ALTER TABLE "orders" ADD COLUMN order_date DATE;',
+      'ALTER TABLE "orders" ALTER COLUMN order_date SET NOT NULL;',
+    ]);
+  });
+});

src/queryKinds/ddl/table/Alter.ts

@@ -199,13 +199,9 @@ export default class AlterTableQuery extends TableQueryDefinition {
    * @returns The SQL string representation of the ALTER TABLE query.
    * @throws Error if the query has not been built yet.
    */
-  public toSQL(): string | string[] {
+  public toSQL(): string[] {
     if (this.builtQuery) this.build();
-    if (!this.builtQuery)
-      throw new Error(
-        "No built query available. Please build the query first.",
-      );
-    return this.builtQuery;
+    return this.builtQuery as string[];
   }
 
   /**

src/queryKinds/ddl/table/Create.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, it } from "vitest";
 import CreateTableQuery from "./Create.js";
 import Column from "../../../queryUtils/Column.js";
 import { Decimal, Varchar } from "../../../types/ColumnTypes.js";
+import QueryKind from "../../../types/QueryKind.js";
 
 
 describe('Create Table Query', () => {
@@ -101,4 +102,68 @@ describe('Create Table Query', () => {
     const query = new CreateTableQuery('empty_table');
     expect(() => query.build()).toThrow('No columns defined for the table.');
   });
+
+  it('should reset the query state', () => {
+    const query = new CreateTableQuery('temp_table')
+      .ifNotExists()
+      .addColumns([
+        Column('id', 'INT').primaryKey().notNull()
+      ]);
+
+    query.reset();
+
+    expect(() => query.build()).toThrow('Table name is not set.');
+  });
+
+  it('should return toSQL correctly', () => {
+    const query = new CreateTableQuery('logs')
+      .addColumns(Column('id', 'INT').primaryKey().notNull())
+      .addColumns(Column('message', Varchar(255)).notNull());
+
+    expect(query.toSQL()).toBe(
+      'CREATE TABLE "logs" (\n  id INT PRIMARY KEY,\n  message VARCHAR(255) NOT NULL\n);'
+    );
+  });
+
+  it('should be able to handle setting columns', () => {
+    const query = new CreateTableQuery('employees')
+      .setColumns([
+        Column('id', 'INT').primaryKey().notNull(),
+        Column('first_name', Varchar(50)).notNull(),
+        Column('last_name', Varchar(50)).notNull()
+      ]);
+
+    expect(query.build()).toBe(
+      'CREATE TABLE "employees" (\n  id INT PRIMARY KEY,\n  first_name VARCHAR(50) NOT NULL,\n  last_name VARCHAR(50) NOT NULL\n);'
+    );
+  });
+
+  it('should be able to return its columns array', () => {
+    const columns = [
+      Column('id', 'INT').primaryKey().notNull(),
+      Column('username', Varchar(50)).notNull()
+    ];
+    const query = new CreateTableQuery('accounts')
+      .setColumns(columns);
+
+    expect(query.columns).toEqual(columns);
+  });
+
+  it('should be able to set the table name later', () => {
+    const query = new CreateTableQuery()
+      .table('departments')
+      .addColumns([
+        Column('id', 'INT').primaryKey().notNull(),
+        Column('dept_name', Varchar(100)).notNull()
+      ]);
+
+    expect(query.build()).toBe(
+      'CREATE TABLE "departments" (\n  id INT PRIMARY KEY,\n  dept_name VARCHAR(100) NOT NULL\n);'
+    );
+  });
+
+  it('should return its kind', () => {
+    const query = new CreateTableQuery('audit');
+    expect(query.kind).toBe(QueryKind.CREATE_TABLE);
+  });
 });

src/queryKinds/ddl/table/Create.ts

@@ -17,7 +17,7 @@ export default class CreateTableQuery extends TableQueryDefinition {
     this.tableName = tableName
       ? SqlEscaper.escapeTableName(tableName, this.flavor)
       : "";
-    this.tableColumns = columns ?? [];
+    this.tableColumns = columns;
   }
 
   /**
@@ -98,7 +98,7 @@ export default class CreateTableQuery extends TableQueryDefinition {
     this.tableName = "";
     this.tableColumns = [];
     this.builtQuery = null;
-    this.ifNotExistsFlag = false;
+    this.resetIfNotExists();
     return this;
   }
 
@@ -107,7 +107,8 @@ export default class CreateTableQuery extends TableQueryDefinition {
    * @returns The SQL string representation of the CREATE TABLE query.
    */
   public toSQL(): string {
-    return this.build();
+    if(!this.builtQuery) this.build();
+    return this.builtQuery as string;
   }
 
   /**

src/queryKinds/ddl/table/Drop.test.ts

@@ -0,0 +1,48 @@
+import { describe, expect, it } from "vitest";
+import DropTableQuery from "./Drop.js";
+import QueryKind from "../../../types/QueryKind.js";
+
+describe('Drop Table Query', () => {
+  it('should create a basic DROP TABLE query', () => {
+    const query = new DropTableQuery('users').build();
+    expect(query).toBe('DROP TABLE "users";');
+  });
+
+  it('should be able to set table name later', () => {
+    const query = new DropTableQuery().table('products').build();
+    expect(query).toBe('DROP TABLE "products";');
+  });
+
+  it('should throw if table name is not provided', () => {
+    const query = new DropTableQuery();
+    expect(() => query.build()).toThrow('Table name is required to build DROP TABLE query.');
+  });
+
+  it('should create a DROP TABLE query with IF EXISTS', () => {
+    const query = new DropTableQuery('users').ifExists().build();
+    expect(query).toBe('DROP TABLE IF EXISTS "users";');
+  });
+
+  it('should clone the DropTableQuery instance', () => {
+    const original = new DropTableQuery('orders').ifExists();
+    const cloned = original.clone();
+    expect(cloned).not.toBe(original);
+    expect(cloned.build()).toBe(original.build());
+  });
+
+  it('should reset the DropTableQuery instance', () => {
+    const query = new DropTableQuery('customers').ifExists();
+    query.reset();
+    expect(() => query.build()).toThrow('Table name is required to build DROP TABLE query.');
+  });
+
+  it('should return the correct SQL string representation', () => {
+    const query = new DropTableQuery('employees').ifExists();
+    expect(query.toSQL()).toBe('DROP TABLE IF EXISTS "employees";');
+  });
+
+  it('should return kind as DROP_TABLE', () => {
+    const query = new DropTableQuery('departments');
+    expect(query.kind).toBe(QueryKind.DROP_TABLE);
+  });
+});

src/queryKinds/ddl/table/Drop.ts

@@ -15,6 +15,11 @@ export default class DropTableQuery extends TableQueryDefinition {
       : "";
   }
 
+  public ifExists(): this {
+    this.ifNotExistsFlag = true;
+    return this;
+  }
+
   /**
    * Builds the DROP TABLE SQL query string.
    * @param _deepAnalysis - Optional boolean to indicate if deep analysis is required (default is false).
@@ -39,7 +44,8 @@ export default class DropTableQuery extends TableQueryDefinition {
    * @returns A new DropTableQuery instance with the same properties as the current instance.
    */
   public clone(): DropTableQuery {
-    const cloned = new DropTableQuery(this.tableName);
+    const cloned = new DropTableQuery();
+    cloned.tableName = this.tableName;
     cloned.flavor = this.flavor;
     cloned.ifNotExistsFlag = this.ifNotExistsFlag;
     return cloned;
@@ -53,7 +59,7 @@ export default class DropTableQuery extends TableQueryDefinition {
   public reset(): this {
     this.tableName = "";
     this.builtQuery = null;
-    this.ifNotExistsFlag = false;
+    this.resetIfNotExists();
     return this;
   }
 
@@ -62,7 +68,8 @@ export default class DropTableQuery extends TableQueryDefinition {
    * @returns The SQL string representation of the DROP TABLE query.
    */
   public toSQL(): string {
-    return this.build();
+    if(!this.builtQuery) this.build();
+    return this.builtQuery as string;
   }
 
   /** Getter for the kind of query. */