Fest Fluent Assertions for Guava: Technical Analysis of Fest Fluent Assertions for Guava)

Fest Fluent Assertions for Guava: Technical Principles Analysis In Java programming, Guava is a powerful open source library that provides many efficient and easy -to -use functions and tools.However, sometimes we may need to be more concise and readable to verify various behaviors in the Guava library.To solve this problem, Fest Fluent Assertions for Guava's underlying layer is based on the Fest Fluent Assertions library and has been modified and expanded to provide streamlined assertions like Hamcrest and Assertj. Technical principle analysis The main principle of Fest Fluent Assertions for Guava Library is to verify various behaviors in the Guava library by using Fluent API (stream API).The library by adding custom assertions that matches the Guava library, these assertions are used very smoothly and easy to read. Here are some of the most commonly used assertions and examples of the library: 1. Collection assertion Fest Fluent Assertions for Guava Library provides a wealth of assertions to verify the collection behavior.For example, we can use the `hassize` to assert to verify the size of the collection: List<String> names = Lists.newArrayList("John", "Jane", "Alice"); Assertions.assertThat(names).hasSize(3); 2. Mickling assertion The library also supports the use of the matching device to assert.For example, we can use the `contains` to assert whether to contain specific elements in the set: List<String> names = Lists.newArrayList("John", "Jane", "Alice"); Assertions.assertThat(names).contains("John"); 3. Cache assertation The GUAVA library provides a series of tool categories and interfaces for processing cache.Fest Fluent Assertions for Guava Library to verify the cache behavior by adding an assertion method.For example, we can use the `containskey` to assert whether to verify whether the specified keys in the cache: Cache<String, String> cache = CacheBuilder.newBuilder().build(); cache.put("key", "value"); Assertions.assertThat(cache).containsKey("key"); 4. Election value assertion The GUAVA library provides an Optional type for processing the value that may be NULL.Fest Fluent Assertions for Guava Library provides an assertion method to verify the Optional value.For example, we can use the `iSpReSENT` to assert whether the Optional contains the value of non -NULL: Optional<String> optional = Optional.of("value"); Assertions.assertThat(optional).isPresent(); 5. Odomy The library also provides an assertion method to verify whether the method is thrown out of the expected exception.For example, we can use the `Thrownexception` to assert whether the method is thrown out of a specific type of exception: Assertions.assertThatExceptionOfType(RuntimeException.class) .isThrownBy(() -> { throw new RuntimeException("error"); }); By using an assertion method in the above examples, we can assess the behavior in the Guava library through a smooth and easy way to read. in conclusion Fest Fluent Assertions for Guava is a powerful testing tool that helps us asserting more concise and readable.It expands the Fest FLUENT Assertions library by adding a specific assertion method for the Guava library, enabling us to verify the various behaviors in the Guava library in a smooth way.By using Fest Fluent Assertions for Guava, we can write test code more efficiently and improve the maintenance of the code.