There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: “If all the participants have responded positively, then the coordinator will send a COMMIT message to all of the participants and the distributed transaction will be complete.”

A block of code is set as follows:

BEGIN;
-- execute queries, updates, inserts, deletes …
PREPARE TRANSACTION 'bfa1c57a-d99d-4d74-87a9-3aaabcc754ee';

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

func NewCommandHandlers(
    app application.App,) ddd.CommandHandler
        [ddd.Command] {
    return commandHandlers{
        app: app,

Any command-line input or output is written as follows:

--- PASS: TestApplication_AddItem (0.00s)
    --- PASS: TestApplication_AddItem/NoBasket (0.00s)
    --- PASS: TestApplication_AddItem/NoProduct (0.00s)
    --- PASS: TestApplication_AddItem/NoStore (0.00s)
    --- PASS: TestApplication_AddItem/SaveFailed (0.00s)
    --- PASS: TestApplication_AddItem/Success (0.00s)
PASS

Bold: Indicates a new term, an important word, or words that you see on screen. For instance, words in menus or dialog boxes appear in bold. Here is an example: “The Customers module remains uncoupled from the Order Processing module because we do not have any explicit ties to the Order Processing module in this handler.”

Tips or Important Notes

Appear like this.