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Migrate Hamcrest assertions to AssertJ

org.openrewrite.java.testing.hamcrest.MigrateHamcrestToAssertJ

Migrate Hamcrest assertThat(..) to AssertJ Assertions.

Tags​

  • testing
  • assertj
  • hamcrest

Recipe source​

GitHub, Issue Tracker, Maven Central

info

This recipe is composed of more than one recipe. If you want to customize the set of recipes this is composed of, you can find and copy the GitHub source for the recipe from the link above.

This recipe is available under the Moderne Source Available License.

Definition​

Examples​

Example 1​
Unchanged​
class Biscuit {
    String name;
    Biscuit(String name) {
        this.name = name;
    }

    int getChocolateChipCount() {
        return 10;
    }

    int getHazelnutCount() {
        return 3;
    }
}
Before​
import org.junit.jupiter.api.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.*;

public class BiscuitTest {
    @Test
    public void biscuits() {
        Biscuit theBiscuit = new Biscuit("Ginger");
        Biscuit myBiscuit = new Biscuit("Ginger");
        assertThat(theBiscuit, equalTo(myBiscuit));
        assertThat("chocolate chips", theBiscuit.getChocolateChipCount(), equalTo(10));
        assertThat("hazelnuts", theBiscuit.getHazelnutCount(), equalTo(3));
    }
}
After​
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThat;

public class BiscuitTest {
    @Test
    public void biscuits() {
        Biscuit theBiscuit = new Biscuit("Ginger");
        Biscuit myBiscuit = new Biscuit("Ginger");
        assertThat(theBiscuit).isEqualTo(myBiscuit);
        assertThat(theBiscuit.getChocolateChipCount()).as("chocolate chips").isEqualTo(10);
        assertThat(theBiscuit.getHazelnutCount()).as("hazelnuts").isEqualTo(3);
    }
}
Example 2​
Before​
import org.junit.jupiter.api.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.allOf;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasLength;

class ATest {
    @Test
    void test() {
        String str1 = "Hello world!";
        String str2 = "Hello world!";
        assertThat(str1, allOf(equalTo(str2), hasLength(12)));
    }
}
After​
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThat;

class ATest {
    @Test
    void test() {
        String str1 = "Hello world!";
        String str2 = "Hello world!";
        assertThat(str1)
                .satisfies(
                        arg -> assertThat(arg).isEqualTo(str2),
                        arg -> assertThat(arg).hasSize(12)
                );
    }
}
Example 3​
Before​
import org.junit.jupiter.api.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.anyOf;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasLength;

class ATest {
    @Test
    void test() {
        String str1 = "Hello world!";
        String str2 = "Hello world!";
        assertThat(str1, anyOf(equalTo(str2), hasLength(12)));
    }
}
After​
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThat;

class ATest {
    @Test
    void test() {
        String str1 = "Hello world!";
        String str2 = "Hello world!";
        assertThat(str1)
                .satisfiesAnyOf(
                        arg -> assertThat(arg).isEqualTo(str2),
                        arg -> assertThat(arg).hasSize(12)
                );
    }
}
Example 4​
Unchanged​
class Biscuit {
    String name;
    Biscuit(String name) {
        this.name = name;
    }

    int getChocolateChipCount() {
        return 10;
    }

    int getHazelnutCount() {
        return 3;
    }
}
Before​
import org.junit.jupiter.api.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.*;

public class BiscuitTest {
    @Test
    public void biscuits() {
        Biscuit theBiscuit = new Biscuit("Ginger");
        Biscuit myBiscuit = new Biscuit("Ginger");
        assertThat(theBiscuit, equalTo(myBiscuit));
        assertThat("chocolate chips", theBiscuit.getChocolateChipCount(), equalTo(10));
        assertThat("hazelnuts", theBiscuit.getHazelnutCount(), equalTo(3));
    }
}
After​
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThat;

public class BiscuitTest {
    @Test
    public void biscuits() {
        Biscuit theBiscuit = new Biscuit("Ginger");
        Biscuit myBiscuit = new Biscuit("Ginger");
        assertThat(theBiscuit).isEqualTo(myBiscuit);
        assertThat(theBiscuit.getChocolateChipCount()).as("chocolate chips").isEqualTo(10);
        assertThat(theBiscuit.getHazelnutCount()).as("hazelnuts").isEqualTo(3);
    }
}
Example 5​
Before​
import org.junit.jupiter.api.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.allOf;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasLength;

class ATest {
    @Test
    void test() {
        String str1 = "Hello world!";
        String str2 = "Hello world!";
        assertThat(str1, allOf(equalTo(str2), hasLength(12)));
    }
}
After​
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThat;

class ATest {
    @Test
    void test() {
        String str1 = "Hello world!";
        String str2 = "Hello world!";
        assertThat(str1)
                .satisfies(
                        arg -> assertThat(arg).isEqualTo(str2),
                        arg -> assertThat(arg).hasSize(12)
                );
    }
}
Example 6​
Before​
import org.junit.jupiter.api.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.anyOf;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasLength;

class ATest {
    @Test
    void test() {
        String str1 = "Hello world!";
        String str2 = "Hello world!";
        assertThat(str1, anyOf(equalTo(str2), hasLength(12)));
    }
}
After​
import org.junit.jupiter.api.Test;

import static org.assertj.core.api.Assertions.assertThat;

class ATest {
    @Test
    void test() {
        String str1 = "Hello world!";
        String str2 = "Hello world!";
        assertThat(str1)
                .satisfiesAnyOf(
                        arg -> assertThat(arg).isEqualTo(str2),
                        arg -> assertThat(arg).hasSize(12)
                );
    }
}

Usage​

This recipe has no required configuration options. It can be activated by adding a dependency on org.openrewrite.recipe:rewrite-testing-frameworks in your build file or by running a shell command (in which case no build changes are needed):

  1. Add the following to your build.gradle file:
build.gradle
plugins {
    id("org.openrewrite.rewrite") version("7.6.1")
}

rewrite {
    activeRecipe("org.openrewrite.java.testing.hamcrest.MigrateHamcrestToAssertJ")
    setExportDatatables(true)
}

repositories {
    mavenCentral()
}

dependencies {
    rewrite("org.openrewrite.recipe:rewrite-testing-frameworks:3.8.0")
}
  1. Run gradle rewriteRun to run the recipe.

See how this recipe works across multiple open-source repositories​

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Data Tables​

Source files that had results​

org.openrewrite.table.SourcesFileResults

Source files that were modified by the recipe run.

Column NameDescription
Source path before the runThe source path of the file before the run. null when a source file was created during the run.
Source path after the runA recipe may modify the source path. This is the path after the run. null when a source file was deleted during the run.
Parent of the recipe that made changesIn a hierarchical recipe, the parent of the recipe that made a change. Empty if this is the root of a hierarchy or if the recipe is not hierarchical at all.
Recipe that made changesThe specific recipe that made a change.
Estimated time savingAn estimated effort that a developer to fix manually instead of using this recipe, in unit of seconds.
CycleThe recipe cycle in which the change was made.

Contributors​

Tim te Beek, Knut Wannheden, Jonathan Schnéider, Aleksandar A Simpson