Mobile application

As explained in Contract Testing in Action

Software designed to run on mobile devices and provide functionality through a mobile user interface.

A mobile application is bundled software that runs on a mobile device, presents a mobile user interface, and communicates with external APIs. Because users update bundled releases at different times, reliable API contracts help preserve a seamless experience. section 5.0

When API expectations drift

A movie-search mobile app requests /movies. The app changes its expected release field from a raw date to a year, while the API still returns a date. The mismatch appears only after deployment unless a consumer contract provides earlier feedback. section 5.0

A practical mobile application integration separates responsibilities:

• The data layer calls the external service through a MovieAPI interface and repository. section 5.1.2
• Retrofit maps the /movies response into MoviesDTO and Movie objects before passing data to the presentation layer. section 5.1.2
• An injectable client accepts its base URL, allowing tests to redirect requests to a Pact mock server. section 5.1.2
• Separate mobile and provider contracts let an API evolve for one consumer without silently breaking another. section 1.2

Figure 5.1 Mobile expected response with Year field and movies API actual response with Date field

Compare the mobile client's expected year field with the movies API's actual date field to see how an integration contract can drift. section 5.0

How Contract Testing in Action covers it

How deep it goes

Traces an Android data layer, Retrofit client, response models, test URL injection, and Pact integration, but not broader mobile development.

Examples

Demonstrates a movie-search app, a /movies endpoint, Movie models, Retrofit requests, and mismatched year and date responses.

What it assumes

Assumes foundational contract-testing knowledge and Android familiarity, while supplying implementation context for dependencies, annotations, and data-layer integration.

What you can do after

Apply it via Kotlin, Gradle, JUnit 5, Retrofit, and Pact to model API interactions and verify mobile-provider compatibility.

How it connects

Connects mobile applications with external APIs, data layers, consumer-driven contract testing, provider verification, and Pact Brokers.

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Related concepts

• releaseused by · A software release is a version or set of changes made available to intended recipients for deployment or use.
• data layerhas part · A data layer is an architectural part of a system that organizes access to, management of, or persistence of data for other components.
• Gradleused by · Gradle is an open-source build automation system for defining and executing software build tasks, managing dependencies, and configuring project builds.
• Kotlinused by · Kotlin is a statically typed general-purpose programming language that targets the JVM and other platforms and interoperates with Java.
• clientkind of · A client is a person, organization, device, or software component that receives or uses a product, service, resource, or functionality provided by another entity.
• frontend developmenthas part · Frontend development is the practice of building the user-facing, client-side interfaces and behavior through which people interact with software.

This explainer was generated by Manning's knowledge graph from the text of Contract Testing in Action. The section links point to the parts of the book it draws on.