Align method and field search algorithms with Java semantics #3553

sbrannen · 2023-11-10T15:37:37Z

Overview

As discussed in #3532 (comment), the search algorithms in JUnit 5 that are used to locate methods and fields have historically had the following undesirable characteristic.

A field supersedes (shadows, hides, overrides) a field with the same name in a superclass unless a filter (Predicate) is applied that ignores one of the fields (such as a static check or a check for the presence of a specific annotation).

This also applies to any methods looked up via JUnit 5's reflection support -- for example, lifecycle methods and test methods in JUnit Jupiter.

The JUnit 5 team discussed this topic today and decided to revise our search algorithms to align with Java semantics regarding visibility and overriding.

Specifically, we want to ensure that our search algorithms do not treat something as overridden when it is not overridden according to the Java Virtual Machine Specification (JVMS).

As a consequence, several currently unsupported use cases would become supported -- for example:

Two @TempDir fields with the same name in a superclass and subclass would both be injected.
Two @BeforeEach methods with the same name/signature in a superclass and subclass would both be invoked, if the @BeforeEach method in the superclass is package-private and the subclass resides in a different package (i.e., the @BeforeEach method in the subclass does not @Override the @BeforeEach method in the superclass according to the JVMS).

External Resources

Java Virtual Machine Specification: § 5.4.5, Overriding

Related Issues

Deliverables

Align method and field search algorithms with Java semantics regarding visibility/overridability.
Introduce tests for overridden method support. See comment below.
Introduce a configuration parameter / system property -- for example, junit.platform.reflection.search.useLegacySemantics = true -- that allows a project to revert to the previous behavior.
Document in User Guide.
Document in Release Notes.

The text was updated successfully, but these errors were encountered:

This is a work in progress. Currently based on main (5.11 M1 snapshots) and currently only applied to our method search algorithm. Aside from the renaming of isMethodShadowedByLocalMethods(), this commit should no longer contain changes to ReflectionUtils.findAllMethodsInHierarchy() once 64ed21a has been reverted. See junit-team#3553

sbrannen · 2024-01-07T17:06:24Z

Current work on this issue can be viewed in the following feature branch.

main...sbrannen:junit5:issues/3553-java-visibility-semantics-for-methods-and-fields

This commit reverts the functional changes from commit f30a8d5 and disables the associated tests for the time being. See #3532 See #3553 Closes #3638

This commit reverts the functional changes from commit f30a8d5 and disables the associated tests for the time being. See #3532 See #3553 Closes #3638 (cherry picked from commit 7789d32)

…lgorithms" This reverts commit a670d10. See #3534 See #3553 See #3600

…lgorithms" This reverts commit a670d10. See #3534 See #3553 See #3600 (cherry picked from commit 2f05a7c)

This commit reverts the functional changes from commit 64ed21a and disables the associated tests for the time being. See #3498 See #3500 See #3553 Closes #3600

This commit reverts the functional changes from commit 64ed21a and disables the associated tests for the time being. See #3498 See #3500 See #3553 Closes #3600 (cherry picked from commit c2f49f6)

This is a work in progress. TODO - Introduce JVM system property to switch to legacy search mode. - Update all documentation that mentions hiding/superseding semantics. - User Guide and Javadoc. - Document in Release Notes. See junit-team#3553

See junit-team#3553

This is a work in progress. TODO - Introduce JVM system property to switch to legacy search mode. - Update all documentation that mentions hiding/superseding semantics. - User Guide and Javadoc. - Document in Release Notes. See junit-team#3553

See junit-team#3553

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See junit-team#3553

See junit-team#3553

This is a work in progress. TODO - Introduce JVM system property to switch to legacy search mode. - Update all documentation that mentions hiding/superseding semantics. - User Guide and Javadoc. - Document in Release Notes. See junit-team#3553

See junit-team#3553

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See junit-team#3553

See junit-team#3553

This is a work in progress. TODO - Introduce JVM system property to switch to legacy search mode. - Update all documentation that mentions hiding/superseding semantics. - User Guide and Javadoc. - Document in Release Notes. See junit-team#3553

See junit-team#3553

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See junit-team#3553

See junit-team#3553

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See junit-team#3553

See junit-team#3553

This commit modifies the method and field search algorithms in ReflectionUtils in order to align with standard Java semantics regarding whether a given field or method is visible or overridden according to the rules of the Java language. Specifically, this commit: - Renames isMethodShadowedBy() to isMethodOverriddenBy(). - Revises the logic in isMethodOverriddenBy() to determine if one method overrides another method according to the rules of the Java language. - Revises isFieldShadowedByLocalFields() to always return false for the time being. - Revises existing tests accordingly; introduces new tests for the new behavior; and disables existing tests for the legacy behavior. See #3553

This commit introduces support for the following JVM system property which can be set to "true" to revert to legacy search semantics for fields and methods. junit.platform.reflection.search.useLegacySemantics See #3553

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See #3553

See #3553

sbrannen self-assigned this Nov 10, 2023

github-actions bot added the status: new label Nov 10, 2023

sbrannen added type: enhancement theme: extensions theme: programming model component: Jupiter component: Platform and removed status: new labels Nov 10, 2023

sbrannen changed the title ~~Align method and field search algorithms with Java semantics regarding visibility~~ Align method and field search algorithms with Java semantics Nov 10, 2023

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sbrannen added this to the 5.11 M1 milestone Nov 10, 2023

sbrannen mentioned this issue Jan 7, 2024

Revert changes to method search algorithm #3600

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sbrannen added the status: in progress label Jan 7, 2024

This was referenced Jan 14, 2024

Apply field predicate before searching type hierarchy #3533

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Revert changes to field search algorithm #3638

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sbrannen added a commit that referenced this issue Jan 15, 2024

Revert "Apply field predicate before searching type hierarchy"

7789d32

This commit reverts the functional changes from commit f30a8d5 and disables the associated tests for the time being. See #3532 See #3553 Closes #3638

sbrannen added a commit that referenced this issue Jan 15, 2024

Revert "Harmonize application of method and field filters in search a…

2f05a7c

…lgorithms" This reverts commit a670d10. See #3534 See #3553 See #3600

sbrannen added a commit that referenced this issue Jan 15, 2024

Revert "Harmonize application of method and field filters in search a…

63d464d

…lgorithms" This reverts commit a670d10. See #3534 See #3553 See #3600 (cherry picked from commit 2f05a7c)

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sbrannen added the type: bug label Feb 3, 2024

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sbrannen added a commit to sbrannen/junit5 that referenced this issue Feb 28, 2024

Introduce useLegacySemantics flag for field and method searches

c77d94e

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Feb 28, 2024

Introduce useLegacySemantics flag for field and method searches

211a410

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Mar 17, 2024

Introduce useLegacySemantics flag for field and method searches

6142cff

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Mar 17, 2024

Delete tests for legacy semantics for field and method searches

1c789b3

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Mar 17, 2024

Document method and field inheritance semantics

cea9641

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Mar 21, 2024

Introduce useLegacySemantics flag for field and method searches

eda4eda

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Mar 21, 2024

Delete tests for legacy semantics for field and method searches

809bd0e

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Mar 21, 2024

Document method and field inheritance semantics

b0d502b

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Apr 6, 2024

Introduce useLegacySemantics flag for field and method searches

c8966e6

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Apr 6, 2024

Delete tests for legacy semantics for field and method searches

32793d8

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Apr 6, 2024

Document method and field inheritance semantics

5f1e7d3

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Apr 6, 2024

Align method and field search algorithms with Java semantics

db04c94

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Apr 6, 2024

Introduce useLegacySemantics flag for field and method searches

afc7d3e

See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Apr 6, 2024

Delete tests for legacy semantics for field and method searches

8856e11

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See junit-team#3553

sbrannen added a commit to sbrannen/junit5 that referenced this issue Apr 6, 2024

Document method and field inheritance semantics

c9839a9

See junit-team#3553

sbrannen added a commit that referenced this issue Apr 7, 2024

Delete tests for legacy semantics for field and method searches

ef17fc0

I'm intentionally leaving this commit in the Git history, in case we later decide to re-introduce these tests. See #3553

sbrannen added a commit that referenced this issue Apr 7, 2024

Document method and field inheritance semantics

656b9ed

See #3553

sbrannen closed this as completed in 3e5a5df Apr 7, 2024

sbrannen removed the status: in progress label Apr 7, 2024

sbrannen mentioned this issue Apr 13, 2024

Create 5.11 upgrade guide wiki page #3774

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Align method and field search algorithms with Java semantics #3553

Align method and field search algorithms with Java semantics #3553

sbrannen commented Nov 10, 2023 •

edited

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Align method and field search algorithms with Java semantics #3553

Align method and field search algorithms with Java semantics #3553

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sbrannen commented Nov 10, 2023 • edited

Overview

External Resources

Related Issues

Deliverables

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sbrannen commented Jan 7, 2024

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sbrannen commented Nov 10, 2023 •

edited