sbt in Action: The simple Scala build tool

282 Pages·2015·6.24 MB·English

by  Joshua Suereth

The simple Scala build tool
Joshua Suereth
Matthew Farwell
M A N N I N G
www.it-ebooks.info
sbt in Action
Licensed to tracwy wmwo.oitr-ee b<[email protected]>
Licensed to tracwy wmwo.oitr-ee b<[email protected]>
sbt in Action
THE SIMPLE SCALA BUILD TOOL
JOSHUA SUERETH
MATTHEW FARWELL
MANNING
SHELTER ISLAND
Licensed to tracwy wmwo.oitr-ee b<[email protected]>
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contents
preface xi
acknowledgments xiii
about this book xv
about the cover illustration xviii
PART 1 WHY SBT?...........................................................1
1 Why sbt? 3
1.1 Why a build tool? 4
1.2 Apache Ant 6
1.3 Apache Maven 8
Build definition 8 ■ Maven workflow—default lifecycle 9
Adding another task to a Maven build 11 ■ Advantages of
Maven 11 ■ Limitations of Maven 11
1.4 Gradle 12
What is Gradle? 12 ■ Gradle workflow 13 ■ Adding another
task to a Gradle build 13 ■ Advantages of Gradle 14
Limitations of Gradle 14
1.5 Why sbt? 15
How sbt works 15 ■ Plugin architecture vs. tasks 16
Phases vs. task dependencies 18 ■ Passing information around
your build 18 ■ Working with Scala 19 ■ Multiproject
builds 20 ■ Dependency resolution 21
v
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vi CONTENTS
1.6 Interactivity/reactivity of sbt 21
Quicker compilation and testing cycle 21 ■ Quicker compilation
and testing cycle 21 ■ sbt and the Scala REPL—the console
command 22
1.7 Summary 23
2 Getting started 24
2.1 Setting up sbt 25
Setting the PATH in bash (for Linux/Mac) 25
Running sbt 26
2.2 Setting up a build 27
Tasks 28 ■ Settings 29
2.3 Running code 31
2.4 Testing code 35
Running tasks when sources change 37 ■ Selecting tests with
interactive tasks 38
2.5 Summary 39
PART 2 UNDERSTANDING SBT’S CORE CONCEPTS............41
3 Core concepts 43
3.1 Creating builds 44
3.2 Defining settings 44
Initializations 47
3.3 Creating and executing tasks 49
Task dependencies 52
3.4 Using configurations 54
3.5 Defining with subprojects 55
3.6 Putting it all together 60
3.7 Summary 64
4 The default build 66
4.1 Compiling your code 67
4.2 Finding your sources 68
Standard organization of sources 68 ■ Testing sources 71
Custom organization of sources 72 ■ Filtering the source
you want 74
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CONTENTS vii
4.3 Depending on libraries 75
Unmanaged dependencies 76 ■ Managed dependencies 76
Managed dependencies and configurations 79
4.4 Packaging your project 80
Identifying your project 82
4.5 Summary 83
PART 3 WORKING WITH SBT ...........................................85
5 Testing 87
5.1 Configuring specs2 with sbt 88
Reports and forking tests 90 ■ Digging deeper: other
options for forking 93
5.2 JUnit and using custom code 94
Report generation with JUnit 95
5.3 ScalaCheck 98
5.4 Integration testing 102
ScalaTest and Selenium 102 ■ Challenges of integration
testing 104 ■ Adding integration tests to sbt 105
5.5 Summary 109
6 The IO and Process libraries 110
6.1 Packaging using processes 111
6.2 Packaging using the sbt.IO library 114
6.3 More mappings 116
6.4 Task dependencies 118
6.5 Logging using the sbt logger 119
6.6 Running your build using fork 121
6.7 Linking everything together: dependencies 122
6.8 Linking everything together: processes 124
6.9 Summary 127
7 Accepting user input 128
7.1 Accepting user input with input tasks 130
7.2 Defining an interface with parsers 133
7.3 Defining a database evolution parser 136
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viii CONTENTS
7.4 Helping the user with autocomplete 142
7.5 Summary 144
8 Using plugins and external libraries 146
8.1 Using plugins to check your code 147
8.2 Using the Revolver plugin to restart the application 151
8.3 Creating your uber jar using the assembly plugin 153
8.4 Including a library in your plugin build 155
8.5 Adding a plugin for use in all of your projects—
signing your projects 159
8.6 Adding local credentials for deployment 161
8.7 Summary 161
9 Debugging your build 162
9.1 Running sbt 163
9.2 Making your build compile 165
9.3 Ensuring tasks are run 168
9.4 Resolving dependency conflicts 172
Fixing resolution failures 173 ■ Fixing resolution conflicts 175
9.5 Summary 179
PART 4 EXTENDING SBT ...............................................181
10 Automating workflows with commands 183
10.1 Creating a simple command 184
10.2 Running tasks in parallel 186
10.3 Parsing input with commands 187
10.4 Creating useful help messages 194
10.5 Summary 197
11 Defining a plugin 198
11.1 Reusing code using Scala files 200
11.2 Introducing the AutoPlugin interface 200
Taking a closer look—the plugin definition 203
Taking a closer look—task and setting dependencies 204
11.3 Testing a plugin with the scripted plugin 206
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CONTENTS ix
11.4 Using configurations in your plugin 211
11.5 Adding incremental tasks 215
Adding incremental tasks with .previous—a sneak
preview of 1.0 217
11.6 Making things easy for the user—more about the
AutoPlugin interface 218
11.7 Summary 222
PART 5 DEPLOYING YOUR PROJECTS.............................223
12 Distributing your projects 225
12.1 Publishing a library 226
12.2 Publishing locally 229
12.3 Publishing a simple server 230
12.4 Generating a distribution 232
12.5 Creating a Linux distribution 236
12.6 Summary 239
appendix A What you need to know about Ivy 240
appendix B Migrating to autoplugins 251
appendix C Advanced setting/task API 254
index 257
Licensed to tracwy wmwo.oitr-ee b<[email protected]>