Implement an in-memory databasewqa

pkg/ramdb/ram_test.go

@@ -0,0 +1,70 @@
+package ramdb
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDatabase_From(t *testing.T) {
+	tests := []struct {
+		test           string
+		expectFunc     func(t *testing.T, db *database)
+		expectedExists bool
+	}{
+		{
+			test:           "it should set exist false if table not found",
+			expectFunc:     func(t *testing.T, db *database) {},
+			expectedExists: false,
+		},
+		{
+			test: "it should set exist true if table is found",
+			expectFunc: func(t *testing.T, db *database) {
+				db.CreateTable("test_table")
+			},
+			expectedExists: true,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.test, func(t *testing.T) {
+			db := NewDatabase()
+			tc.expectFunc(t, db)
+
+			table := db.From("test_table")
+
+			assert.Equal(t, table.exists, tc.expectedExists)
+		})
+	}
+}
+
+func TestDatabase_CreateTable(t *testing.T) {
+	tests := []struct {
+		test          string
+		expectFunc    func(t *testing.T, db *database)
+		expectedError error
+	}{
+		{
+			test: "it should error if the table already exists",
+			expectFunc: func(t *testing.T, db *database) {
+				db.CreateTable("test_table")
+			},
+			expectedError: ErrTableExists,
+		},
+		{
+			test:       "it should not return an error on successful table creation",
+			expectFunc: func(t *testing.T, db *database) {},
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.test, func(t *testing.T) {
+			db := NewDatabase()
+			tc.expectFunc(t, db)
+
+			err := db.CreateTable("test_table")
+
+			assert.Equal(t, tc.expectedError, err)
+		})
+	}
+}