Add junit-mockito module: 30 runnable JUnit 6.1.3 / Mockito 5.24.0 interview answers

One test per question, each writing and asserting its own transcript under output/. Covers lifecycle, extensions, parameterized and dynamic tests, mocks vs spies, verification, strict stubs, static and constructor mocking, and flaky tests. Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01CifR2BE7PBvRy5hT8TS9oz
2026-10-26 01:52:44 +00:00
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+TestEngines found on the classpath (ServiceLoader<TestEngine>):
+  junit-jupiter 6.1.3
+Jupiter API version  : 6.1.3
+Platform launcher    : 6.1.3
+Platform engine API  : 6.1.3
+junit-vintage engine : not on the classpath
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+junit-jupiter-api 5.14.4 : class-file major version 52 (Java 8), MethodOrderer$Alphanumeric entries in jar: 1
+junit-jupiter-api 6.1.3 : class-file major version 61 (Java 17), MethodOrderer$Alphanumeric entries in jar: 0
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+class-file major version of org.junit.jupiter.api.Test : 61 (Java 17)
+Class.forName("org.junit.jupiter.api.MethodOrderer$Alphanumeric") -> ClassNotFoundException
+(the 5.14.4 versus 6.1.3 jar comparison is scripts/compare-5-vs-6.sh -> q02-jar-comparison.txt)
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+@BeforeAll (static)
+@BeforeEach on instance #1
+  test second() on instance #1
+@AfterEach on instance #1
+@BeforeEach on instance #2
+  test first() on instance #2
+@AfterEach on instance #2
+@AfterAll (static)
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+@BeforeAll (non-static) on instance #1
+second(): instance #1, counter=1
+first(): instance #1, counter=2
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+outer @BeforeEach
+  outerTest()
+outer @AfterEach
+outer @BeforeEach
+inner @BeforeEach
+  innerTest()
+inner @AfterEach
+outer @AfterEach
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+declared order in the source     : zebra(), apple(), mango(), banana()
+default (no orderer configured)  : [banana(), apple(), mango(), zebra()]
+MethodOrderer.MethodName         : [apple(), banana(), mango(), zebra()]
+MethodOrderer.DisplayName        : [apple(), banana(), mango(), zebra()]
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+assertAll reported 2 failures from 3 assertions:
+order (2 failures)
+	org.opentest4j.AssertionFailedError: quantity ==> expected: <1> but was: <2>
+	org.opentest4j.AssertionFailedError: code ==> expected: <A> but was: <B>
+assertThrows returns the exception: getMessage() = boom
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+assertTimeout            runs the code on the test thread : true
+assertTimeoutPreemptively runs the code on the test thread : false
+assertTimeout failure message (trimmed at ' by '): execution exceeded timeout of 50 ms
+assertTimeoutPreemptively failure message: execution timed out after 50 ms
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+assertionFails() -> FAILED
+assumptionFails() -> ABORTED
+passes() -> SUCCESSFUL
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+declared: beforeAll
+declared: beforeEach
+test class: @BeforeEach method
+declared: beforeTestExecution
+test class: the test body
+declared: afterTestExecution
+declared: afterEach
+declared: afterAll
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+declared: beforeAll
+programmatic(static field): beforeAll
+declared: beforeEach
+programmatic(static field): beforeEach
+declared: beforeTestExecution
+programmatic(static field): beforeTestExecution
+test body
+programmatic(static field): afterTestExecution
+declared: afterTestExecution
+programmatic(static field): afterEach
+declared: afterEach
+programmatic(static field): afterAll
+declared: afterAll
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+custom parameter : Tenant[name=tenant-for-resolvesCustomAndBuiltIn]
+built-in TestInfo: displayName=resolvesCustomAndBuiltIn(Tenant, TestInfo)
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+enumSource(Level) / [1] LOW -> SUCCESSFUL
+enumSource(Level) / [2] HIGH -> SUCCESSFUL
+valueSource(int) / [1] 1 -> SUCCESSFUL
+valueSource(int) / [2] 2 -> SUCCESSFUL
+valueSource(int) / [3] 3 -> SUCCESSFUL
+nullAndEmpty(String) / [1] null -> SUCCESSFUL
+nullAndEmpty(String) / [2] "" -> SUCCESSFUL
+nullAndEmpty(String) / [3] " " -> SUCCESSFUL
+csvSource(String, int) / [1] "apple", "1" -> SUCCESSFUL
+csvSource(String, int) / [2] "banana", "2" -> SUCCESSFUL
+methodSource(String, int) / [1] "x", 10 -> SUCCESSFUL
+methodSource(String, int) / [2] "y", 20 -> SUCCESSFUL
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+display name: csv(String, String) / [1] a="x" b=null -> SUCCESSFUL
+display name: csv(String, String) / [2] a=null b="y" -> SUCCESSFUL
+display name: csv(String, String) / [3] a="" b="z" -> SUCCESSFUL
+display name: csv(String, String) / [4] a=null b="w" -> SUCCESSFUL
+display name: csv(String, String) / [5] a="a,b" b="q" -> SUCCESSFUL
+--- values the test method received ---
+a="x"  b=null
+a=null  b="y"
+a=""  b="z"
+a=null  b="w"
+a="a,b"  b="q"
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+@BeforeEach ran (1 time so far)
+squares() / square of 1 -> SUCCESSFUL
+squares() / square of 2 -> SUCCESSFUL
+squares() / square of 3 -> SUCCESSFUL
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+--- no filter ---
+disabled() -> SKIPPED (waiting for the fix in ticket 1234)
+fast() -> SUCCESSFUL
+onlyWithProperty() -> SKIPPED (System property [lab.run.slow] does not exist)
+slow() -> SUCCESSFUL
+--- includeTags("fast") ---
+fast() -> SUCCESSFUL
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+inside the test : dir exists = true, files = 1
+after the test finished : dir exists = false
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+mock: next() -> 0, next() -> 0, real code ran 0 times
+spy : next() -> 1, next() -> 2, real code ran 2 times
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+when(spy.next()).thenReturn(100): real method ran while stubbing = 1 time(s)
+doReturn(100).when(spy).next()   : real method ran while stubbing = 0 time(s)
+both return 100 and 100 after stubbing
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+times / atLeastOnce / never / inOrder: all passed
+--- verify(gw).lookup("zzz") ---
+Wanted but not invoked:
+paymentGateway.lookup("zzz");
+--- verify(gw).audit("declined c") ---
+Argument(s) are different! Wanted:
+paymentGateway.audit("declined c");
+-> at lab.jm.D_MockitoCoreTest.lambda$q20_verify$1(D_MockitoCoreTest.java:90)
+Actual invocations have different arguments:
+paymentGateway.charge("a", 500L);
+-> at lab.jm.OrderService.place(OrderService.java:17)
+--- verify(gw, never()).audit("declined b") ---
+paymentGateway.audit("declined b");
+Never wanted here:
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+when(gw.charge("a", anyLong())) -> InvalidUseOfMatchersException
+Invalid use of argument matchers!
+2 matchers expected, 1 recorded:
+-> at lab.jm.D_MockitoCoreTest.lambda$q21_matchersAndCaptor$0(D_MockitoCoreTest.java:103)
+ArgumentCaptor saw account=zoe cents=1234
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+MockitoExtension (default strictness):
+  unusedStub() -> FAILED
+  org.mockito.exceptions.misusing.UnnecessaryStubbingException
+    
+    Unnecessary stubbings detected.
+    Clean & maintainable test code requires zero unnecessary code.
+    Following stubbings are unnecessary (click to navigate to relevant line of code):
+      1. -> at lab.jm.fixtures.MockitoFixtures$StrictByDefault.unusedStub(MockitoFixtures.java:25)
+    Please remove unnecessary stubbings or use 'lenient' strictness. More info: javadoc for UnnecessaryStubbingException class.
+@MockitoSettings(strictness = LENIENT):
+  unusedStub() -> SUCCESSFUL
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+consecutive stubbing: true, false
+third call throws   : gateway down
+void method via doThrow: audit store full
+thenAnswer / BDD willAnswer: lookup("7") = user-7
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+FinalPricer is final: true
+mock(FinalPricer.class).price(3) = 999 (real code would give 30)
+mock.getClass() == FinalPricer.class : true
+default MockMaker : org.mockito.internal.creation.bytebuddy.InlineByteBuddyMockMaker
+class-file major version of org.mockito.Mockito : 55 (Java 11)
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+before            : REAL-ID
+inside the scope  : MOCK-ID
+other thread sees : REAL-ID
+after the scope   : REAL-ID
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+before : RECEIPT[tea]
+inside : FAKE [tea]
+constructed during the scope: 1
+after  : RECEIPT[tea]
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+Mockito is currently self-attaching to enable the inline-mock-maker. This will no longer work in future releases of the JDK. Please add Mockito as an agent to your build as described in Mockito's documentation: https://javadoc.io/doc/org.mockito/mockito-core/latest/org.mockito/org/mockito/Mockito.html#0.3
+WARNING: A Java agent has been loaded dynamically (~/.m2/repository/net/bytebuddy/byte-buddy-agent/1.17.7/byte-buddy-agent-1.17.7.jar)
+WARNING: If a serviceability tool is in use, please run with -XX:+EnableDynamicAgentLoading to hide this warning
+WARNING: If a serviceability tool is not in use, please run with -Djdk.instrument.traceUsage for more information
+WARNING: Dynamic loading of agents will be disallowed by default in a future release
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+int            -> 0
+boolean        -> false
+String         -> null
+List<String>   -> []
+Optional<String> -> Optional.empty
+long           -> 0
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+--- order a_, b_ (alphabetical) ---
+a_registersUser() -> SUCCESSFUL
+b_assumesUserExists() -> SUCCESSFUL
+--- order b_, a_ (reversed) ---
+b_assumesUserExists() -> FAILED
+a_registersUser() -> SUCCESSFUL
+  AssertionFailedError: registry should contain the user registered by another test ==> expected: <1> but was: <0>
+--- time: the same code with an injected Clock ---
+acceptsOrders() at 10:00 UTC : true
+acceptsOrders() at 23:30 UTC : false
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+failsOnThirdRepetition(RepetitionInfo) / repetition 1 of 6 -> SUCCESSFUL
+failsOnThirdRepetition(RepetitionInfo) / repetition 2 of 6 -> SUCCESSFUL
+failsOnThirdRepetition(RepetitionInfo) / repetition 3 of 6 -> FAILED
+failsOnThirdRepetition(RepetitionInfo) / repetition 4 of 6 -> SKIPPED (Failure threshold [1] exceeded)
+failsOnThirdRepetition(RepetitionInfo) / repetition 5 of 6 -> SKIPPED (Failure threshold [1] exceeded)
+failsOnThirdRepetition(RepetitionInfo) / repetition 6 of 6 -> SKIPPED (Failure threshold [1] exceeded)
+withoutThreshold(RepetitionInfo) / repetition 1 of 6 -> SUCCESSFUL
+withoutThreshold(RepetitionInfo) / repetition 2 of 6 -> SUCCESSFUL
+withoutThreshold(RepetitionInfo) / repetition 3 of 6 -> FAILED
+withoutThreshold(RepetitionInfo) / repetition 4 of 6 -> SUCCESSFUL
+withoutThreshold(RepetitionInfo) / repetition 5 of 6 -> SUCCESSFUL
+withoutThreshold(RepetitionInfo) / repetition 6 of 6 -> SUCCESSFUL
+failed=2 skipped=3