test-quality

Name: test-quality
Author: decebals

686stars133forks

How to install test-quality?

decebals/claude-code-java/test-quality

$npx -y skills add decebals/claude-code-java --skill test-quality

Installs into the current project.

Summary

Write high-quality JUnit 5 tests with AssertJ assertions. Use when user says "add tests", "write tests", "improve test coverage", or when reviewing/creating test classes for Java code.

Files · 1

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SKILL.md

1	# Test Quality Skill (JUnit 5 + AssertJ)
2
3	Write high-quality, maintainable tests for Java projects using modern best practices.
4
5	## When to Use
6	- Writing new test classes
7	- Reviewing/improving existing tests
8	- User asks to "add tests" / "improve test coverage"
9	- Code review mentions missing tests
10
11	## Framework Preferences
12
13	### JUnit 5 (Jupiter)
14	```java
15	import org.junit.jupiter.api.Test;
16	import org.junit.jupiter.api.DisplayName;
17	import org.junit.jupiter.api.BeforeEach;
18	import org.junit.jupiter.api.Nested;
19	import static org.assertj.core.api.Assertions.*;
20	```
21
22	### AssertJ over standard assertions
23	✅ Use AssertJ:
24	```java
25	assertThat(plugin.getState())
26	.as("Plugin should be started after initialization")
27	.isEqualTo(PluginState.STARTED);
28
29	assertThat(plugins)
30	.hasSize(3)
31	.extracting(Plugin::getId)
32	.containsExactly("plugin1", "plugin2", "plugin3");
33	```
34
35	❌ Avoid JUnit assertions:
36	```java
37	assertEquals(PluginState.STARTED, plugin.getState()); // Less readable
38	assertTrue(plugins.size() == 3); // Less descriptive failures
39	```
40
41	## Test Structure (AAA Pattern)
42
43	Always use Arrange-Act-Assert pattern:
44
45	```java
46	@Test
47	@DisplayName("Should load plugin from valid directory")
48	void shouldLoadPluginFromValidDirectory() {
49	// Arrange - Setup test data and dependencies
50	Path pluginDir = Paths.get("test-plugins/valid-plugin");
51	PluginLoader loader = new DefaultPluginLoader();
52
53	// Act - Execute the behavior being tested
54	Plugin plugin = loader.load(pluginDir);
55
56	// Assert - Verify results
57	assertThat(plugin)
58	.isNotNull()
59	.extracting(Plugin::getId, Plugin::getVersion)
60	.containsExactly("test-plugin", "1.0.0");
61	}
62	```
63
64	## Naming Conventions
65
66	### Test class names
67	```java
68	// Class under test: PluginManager
69	PluginManagerTest // ✅ Simple, standard
70	PluginManagerShould // ✅ BDD style (if team prefers)
71	TestPluginManager // ❌ Avoid
72	```
73
74	### Test method names
75
76	Option 1: should_expectedBehavior_when_condition (descriptive)
77	```java
78	@Test
79	void should_throwException_when_pluginDirectoryNotFound() { }
80
81	@Test
82	void should_returnEmptyList_when_noPluginsAvailable() { }
83
84	@Test
85	void should_loadPluginsInDependencyOrder_when_multipleDependencies() { }
86	```
87
88	Option 2: Natural language with @DisplayName (cleaner code)
89	```java
90	@Test
91	@DisplayName("Should load all plugins from directory")
92	void loadAllPlugins() { }
93
94	@Test
95	@DisplayName("Should throw exception when plugin descriptor is invalid")
96	void invalidPluginDescriptor() { }
97	```
98
99	## AssertJ Power Features
100
101	### Collection assertions
102	```java
103	// Basic collection checks
104	assertThat(plugins)
105	.isNotEmpty()
106	.hasSize(2)
107	.doesNotContainNull();
108
109	// Advanced filtering and extraction
110	assertThat(plugins)
111	.filteredOn(p -> p.getState() == PluginState.STARTED)
112	.extracting(Plugin::getId)
113	.containsExactlyInAnyOrder("plugin-a", "plugin-b");
114
115	// All elements match condition
116	assertThat(plugins)
117	.allMatch(p -> p.getVersion() != null, "All plugins have version");
118	```
119
120	### Exception assertions
121	```java
122	// Basic exception check
123	assertThatThrownBy(() -> loader.load(invalidPath))
124	.isInstanceOf(PluginException.class)
125	.hasMessageContaining("Invalid plugin descriptor");
126
127	// Detailed exception verification
128	assertThatThrownBy(() -> manager.startPlugin("missing-plugin"))
129	.isInstanceOf(PluginException.class)
130	.hasMessageContaining("Plugin not found")
131	.hasCauseInstanceOf(IllegalArgumentException.class)
132	.hasNoCause(); // or verify cause chain
133
134	// With assertThatExceptionOfType (more readable)
135	assertThatExceptionOfType(PluginException.class)
136	.isThrownBy(() -> loader.load(invalidPath))
137	.withMessageContaining("Invalid")
138	.withMessageMatching("Invalid .* descriptor");
139	```
140
141	### Object assertions
142	```java
143	// Extract and verify multiple properties
144	assertThat(plugin)
145	.isNotNull()
146	.extracting("id", "version", "state")
147	.containsExactly("my-plugin", "1.0", PluginState.STARTED);
148
149	// Using method references (type-safe)
150	assertThat(plugin)
151	.extracting(Plugin::getId, Plugin::getVersion, Plugin::getState)
152	.containsExactly("my-plugin", "1.0", PluginState.STARTED);
153
154	// Field by field comparison
155	assertThat(actualPlugin)
156	.usingRecursiveComparison()
157	.isEqualTo(expectedPlugin);
158	```
159
160	### Soft assertions (multiple checks)
161	```java
162	@Test
163	void shouldHaveValidPluginDescriptor() {
164	SoftAssertions softly = new SoftAssertions();
165
166	softly.assertThat(descriptor.getId())
167	.as("Plugin ID")
168	.isNotBlank()
169	.matches("[a-z0-9-]+");
170
171	softly.assertThat(descriptor.getVersion())
172	.as("Plugin version")
173	.matches("\\d+\\.\\d+\\.\\d+");
174
175	softly.assertThat(descriptor.getDependencies())
176	.as("Dependencies")

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test-quality

686stars133forks

View on GitHub

How to install test-quality?

decebals/claude-code-java/test-quality

$npx -y skills add decebals/claude-code-java --skill test-quality

Installs into the current project.

Summary

Write high-quality JUnit 5 tests with AssertJ assertions. Use when user says "add tests", "write tests", "improve test coverage", or when reviewing/creating test classes for Java code.

Files · 1

View on GitHub

SKILL.md

1	# Test Quality Skill (JUnit 5 + AssertJ)
2
3	Write high-quality, maintainable tests for Java projects using modern best practices.
4
5	## When to Use
6	- Writing new test classes
7	- Reviewing/improving existing tests
8	- User asks to "add tests" / "improve test coverage"
9	- Code review mentions missing tests
10
11	## Framework Preferences
12
13	### JUnit 5 (Jupiter)
14	```java
15	import org.junit.jupiter.api.Test;
16	import org.junit.jupiter.api.DisplayName;
17	import org.junit.jupiter.api.BeforeEach;
18	import org.junit.jupiter.api.Nested;
19	import static org.assertj.core.api.Assertions.*;
20	```
21
22	### AssertJ over standard assertions
23	✅ Use AssertJ:
24	```java
25	assertThat(plugin.getState())
26	.as("Plugin should be started after initialization")
27	.isEqualTo(PluginState.STARTED);
28
29	assertThat(plugins)
30	.hasSize(3)
31	.extracting(Plugin::getId)
32	.containsExactly("plugin1", "plugin2", "plugin3");
33	```
34
35	❌ Avoid JUnit assertions:
36	```java
37	assertEquals(PluginState.STARTED, plugin.getState()); // Less readable
38	assertTrue(plugins.size() == 3); // Less descriptive failures
39	```
40
41	## Test Structure (AAA Pattern)
42
43	Always use Arrange-Act-Assert pattern:
44
45	```java
46	@Test
47	@DisplayName("Should load plugin from valid directory")
48	void shouldLoadPluginFromValidDirectory() {
49	// Arrange - Setup test data and dependencies
50	Path pluginDir = Paths.get("test-plugins/valid-plugin");
51	PluginLoader loader = new DefaultPluginLoader();
52
53	// Act - Execute the behavior being tested
54	Plugin plugin = loader.load(pluginDir);
55
56	// Assert - Verify results
57	assertThat(plugin)
58	.isNotNull()
59	.extracting(Plugin::getId, Plugin::getVersion)
60	.containsExactly("test-plugin", "1.0.0");
61	}
62	```
63
64	## Naming Conventions
65
66	### Test class names
67	```java
68	// Class under test: PluginManager
69	PluginManagerTest // ✅ Simple, standard
70	PluginManagerShould // ✅ BDD style (if team prefers)
71	TestPluginManager // ❌ Avoid
72	```
73
74	### Test method names
75
76	Option 1: should_expectedBehavior_when_condition (descriptive)
77	```java
78	@Test
79	void should_throwException_when_pluginDirectoryNotFound() { }
80
81	@Test
82	void should_returnEmptyList_when_noPluginsAvailable() { }
83
84	@Test
85	void should_loadPluginsInDependencyOrder_when_multipleDependencies() { }
86	```
87
88	Option 2: Natural language with @DisplayName (cleaner code)
89	```java
90	@Test
91	@DisplayName("Should load all plugins from directory")
92	void loadAllPlugins() { }
93
94	@Test
95	@DisplayName("Should throw exception when plugin descriptor is invalid")
96	void invalidPluginDescriptor() { }
97	```
98
99	## AssertJ Power Features
100
101	### Collection assertions
102	```java
103	// Basic collection checks
104	assertThat(plugins)
105	.isNotEmpty()
106	.hasSize(2)
107	.doesNotContainNull();
108
109	// Advanced filtering and extraction
110	assertThat(plugins)
111	.filteredOn(p -> p.getState() == PluginState.STARTED)
112	.extracting(Plugin::getId)
113	.containsExactlyInAnyOrder("plugin-a", "plugin-b");
114
115	// All elements match condition
116	assertThat(plugins)
117	.allMatch(p -> p.getVersion() != null, "All plugins have version");
118	```
119
120	### Exception assertions
121	```java
122	// Basic exception check
123	assertThatThrownBy(() -> loader.load(invalidPath))
124	.isInstanceOf(PluginException.class)
125	.hasMessageContaining("Invalid plugin descriptor");
126
127	// Detailed exception verification
128	assertThatThrownBy(() -> manager.startPlugin("missing-plugin"))
129	.isInstanceOf(PluginException.class)
130	.hasMessageContaining("Plugin not found")
131	.hasCauseInstanceOf(IllegalArgumentException.class)
132	.hasNoCause(); // or verify cause chain
133
134	// With assertThatExceptionOfType (more readable)
135	assertThatExceptionOfType(PluginException.class)
136	.isThrownBy(() -> loader.load(invalidPath))
137	.withMessageContaining("Invalid")
138	.withMessageMatching("Invalid .* descriptor");
139	```
140
141	### Object assertions
142	```java
143	// Extract and verify multiple properties
144	assertThat(plugin)
145	.isNotNull()
146	.extracting("id", "version", "state")
147	.containsExactly("my-plugin", "1.0", PluginState.STARTED);
148
149	// Using method references (type-safe)
150	assertThat(plugin)
151	.extracting(Plugin::getId, Plugin::getVersion, Plugin::getState)
152	.containsExactly("my-plugin", "1.0", PluginState.STARTED);
153
154	// Field by field comparison
155	assertThat(actualPlugin)
156	.usingRecursiveComparison()
157	.isEqualTo(expectedPlugin);
158	```
159
160	### Soft assertions (multiple checks)
161	```java
162	@Test
163	void shouldHaveValidPluginDescriptor() {
164	SoftAssertions softly = new SoftAssertions();
165
166	softly.assertThat(descriptor.getId())
167	.as("Plugin ID")
168	.isNotBlank()
169	.matches("[a-z0-9-]+");
170
171	softly.assertThat(descriptor.getVersion())
172	.as("Plugin version")
173	.matches("\\d+\\.\\d+\\.\\d+");
174
175	softly.assertThat(descriptor.getDependencies())
176	.as("Dependencies")

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Type