uber/NullAway

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A tool to help eliminate NullPointerExceptions (NPEs) in your Java code with low build-time overhead

Stars: 4.1k
Forks: 370
Open beginner issues: 0
Indexed issues: 138
Avg merge: 1d 13h
Merged PRs (30d): 68

Dominant language: Java
License: MIT
Last GitHub push: Sep 18, 2026
Latest indexed: Sep 19, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted

Beginner friendly Everything

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138 open issues indexed

Handle fields in JDK javac plugin Open

jdk-models jspecify

Difficulty 3/5 1-2 days Newbie friendliness 55/100

uber/NullAway#1862 · Opened Sep 19, 2026
Dependency Dashboard Open

Difficulty 5/5 Over a week Newbie friendliness 20/100

uber/NullAway#1859 · Opened Sep 18, 2026
Allow nullable type arguments in wildcard-typed array stores Open

uber/NullAway#1856 · 1 assignee · Opened Sep 17, 2026
JSpecify: nullable upper bound is lost when reading a generic field through ? super Open

false negative jspecify

Difficulty 4/5 3-5 days Newbie friendliness 55/100

uber/NullAway#1854 · 1 comment · Opened Sep 17, 2026
False positive with HandleWildcardGenerics on a self-referential wildcard bound read from another module Open

jspecify

Difficulty 4/5 3-5 days Newbie friendliness 48/100

uber/NullAway#1851 · 3 comments · 1 reaction · Opened Sep 16, 2026
Stop relying on mutable WildcardType.bound outside validated contexts Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

uber/NullAway#1850 · Opened Sep 16, 2026
JSpecify mode: false positive passing null to `Consumer<@Nullable V>` obtained through a wildcard receiver Open

false positive jspecify

Difficulty 4/5 3-5 days Newbie friendliness 68/100

uber/NullAway#1847 · Opened Sep 15, 2026
JSpecify mode: NullPointerException when passing a value read through a `? super` wildcard receiver Open

crash jspecify

Difficulty 3/5 1-2 days Newbie friendliness 72/100

uber/NullAway#1846 · Opened Sep 15, 2026
Avoid stale wildcard bounds after javac supertype inspection Open

uber/NullAway#1840 · 1 assignee · Opened Sep 10, 2026
Support nullability inference for generic constructors in diamond calls Open

uber/NullAway#1825 · 1 comment · 1 assignee · Opened Sep 8, 2026
JSpecifyExperimental: false positive for addAll with ? element type Open

Difficulty 3/5 1-2 days Newbie friendliness 68/100

uber/NullAway#1822 · 5 comments · Opened Sep 7, 2026
[JSpecifyExperimental] False positive `dereferenced expression is @Nullable` in Stream pipeline after `Class::cast` Open

false positive jspecify

uber/NullAway#1808 · 1 comment · 1 reaction · 1 assignee · Opened Sep 3, 2026
Better reason about maps with `@Nullable` values in JSpecify mode Open

false negative jspecify

Difficulty 3/5 1-2 days Newbie friendliness 45/100

uber/NullAway#1805 · Opened Sep 3, 2026
Nullability of java.util.stream.Collectors.partitioningBy Open

enhancement false positive

Difficulty 3/5 1-2 days Newbie friendliness 68/100

uber/NullAway#1797 · 1 comment · Opened Sep 2, 2026
Generic method inference differs between source and bytecode before JDK 17.0.19 Open

Difficulty 3/5 1-2 days Newbie friendliness 48/100

uber/NullAway#1791 · 6 comments · Opened Aug 31, 2026
Inference failure calling unmarked method Open

bug jspecify

Difficulty 4/5 3-5 days Newbie friendliness 50/100

uber/NullAway#1790 · 1 comment · Opened Aug 30, 2026
JSpecifyExperimental: Support smart cast for Class.getAnnotation after Class.isAnnotationPresent check Open

lowpriority

Difficulty 3/5 1-2 days Newbie friendliness 68/100

uber/NullAway#1766 · 3 comments · Opened Aug 28, 2026
Remove `AccessPathNullnessAnalysis` from context and instead just have it as an instance field of `NullAway` Open

cleanup

Difficulty 4/5 3-5 days Newbie friendliness 45/100

uber/NullAway#1738 · 1 comment · Opened Aug 24, 2026
JSpecify: false positive when a method returns `? extends T` and `T` has a `@Nullable` upper bound (support `NO_CHANGE` nullness operator better) Open

highpriority jspecify

Difficulty 4/5 3-5 days Newbie friendliness 62/100

uber/NullAway#1727 · 5 comments · Opened Aug 24, 2026
Look into call sites passing `null` for overridden method type where they should be consulting library models Open

jspecify

Difficulty 3/5 1-2 days Newbie friendliness 48/100

uber/NullAway#1724 · Opened Aug 23, 2026
Check our handling of captured array types Open

Difficulty 3/5 1-2 days Newbie friendliness 58/100

uber/NullAway#1688 · Opened Aug 8, 2026
Remove old workaround code for reading type use annotations from bytecode Open

Difficulty 4/5 3-5 days Newbie friendliness 50/100

uber/NullAway#1639 · Opened Jul 19, 2026
JSpecify: infer diamond type-argument nullability from constructor arguments without a target type Open

jspecify

Difficulty 4/5 3-5 days Newbie friendliness 45/100

uber/NullAway#1633 · Opened Jul 17, 2026
Update Caffeine JMH benchmark once it builds again with NullAway Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

uber/NullAway#1629 · 5 comments · Opened Jul 15, 2026
Downcasting (CastToNonNullMethod) does NOT propagate to the other occurrences of the same expression Open

Difficulty 3/5 1-2 days Newbie friendliness 55/100

uber/NullAway#1628 · 4 comments · Opened Jul 9, 2026
Add some kind of `@PolyNull`-like support within library models? Open

highpriority jspecify

uber/NullAway#1616 · 10 comments · 1 assignee · Opened Jun 19, 2026
Is rejecting `String.class` for a `Class<@Nullable String>` parameter intended? Open

Difficulty 4/5 3-5 days Newbie friendliness 48/100

uber/NullAway#1595 · 2 comments · 1 reaction · Opened Jun 8, 2026
Custom library model for `ExecutableElement#getEnclosingElement` not working Open

Difficulty 4/5 3-5 days Newbie friendliness 30/100

uber/NullAway#1590 · Opened Jun 4, 2026
Enhance generic method inference to compute mappings from type variables to full types? Open

jspecify

Difficulty 5/5 Over a week Newbie friendliness 25/100

uber/NullAway#1585 · Opened May 25, 2026
Compute upper bounds of wildcards more correctly Open

jspecify

Difficulty 4/5 3-5 days Newbie friendliness 52/100

uber/NullAway#1576 · Opened May 13, 2026
Report inference failures as errors by default Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

uber/NullAway#1551 · 1 comment · Opened Apr 26, 2026
When using @Nullable Object... as a parameter, NullAway will prompt an error within the method: [NullAway] incompatible types: @Nullable Object [] cannot be converted to Object [] Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

uber/NullAway#1535 · 2 comments · Opened Apr 15, 2026
Handle @NullUnmarked methods with explicit @NonNull annotations in JDK javac plugin Open

jspecify

Difficulty 4/5 3-5 days Newbie friendliness 45/100

uber/NullAway#1498 · Opened Mar 25, 2026
False-positive warning on Objects.requireNonNullElse Open

enhancement

Difficulty 3/5 1-2 days Newbie friendliness 42/100

uber/NullAway#1493 · 1 comment · Opened Mar 12, 2026
Stream handling failing when using multiple filters Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 45/100

uber/NullAway#1492 · 4 comments · Opened Mar 10, 2026
Handle nested restrictive annotations on type variables in `@NullUnmarked` code Open

jspecify

Difficulty 3/5 1-2 days Newbie friendliness 45/100

uber/NullAway#1488 · Opened Mar 4, 2026
False positive after validating an array with nullable elements Open

lowpriority

Difficulty 4/5 3-5 days Newbie friendliness 35/100

uber/NullAway#1476 · 1 comment · Opened Feb 18, 2026
JSpecify: handle constructor calls using `<>` passed as an argument to generic method calls Open

Difficulty 5/5 Over a week Newbie friendliness 25/100

uber/NullAway#1470 · 3 reactions · Opened Feb 15, 2026
JSpecify: handle interactions between constructor references and generic method inference Open

jspecify

Difficulty 5/5 Over a week Newbie friendliness 25/100

uber/NullAway#1468 · Opened Feb 12, 2026
`Stream#filter(..)`-based nullability is not preserved between methods Open

enhancement

Difficulty 4/5 3-5 days Newbie friendliness 48/100

uber/NullAway#1420 · 1 comment · Opened Dec 31, 2025
Auto-fix all new Error Prone warnings due to targeting JDK 17 Open

Difficulty 3/5 1-2 days Newbie friendliness 45/100

uber/NullAway#1398 · 2 comments · 1 reaction · Opened Dec 23, 2025
False positive when using `return null` in lambda when return type is declared `@Nullable` Open

Difficulty 4/5 3-5 days Newbie friendliness 45/100

uber/NullAway#1389 · 5 comments · 1 reaction · Opened Dec 22, 2025
Properly re-introduce annotations on types of `IdentifierTree`s Open

jspecify

Difficulty 5/5 Over a week Newbie friendliness 35/100

uber/NullAway#1379 · 1 comment · Opened Dec 17, 2025
Add proper support for wildcards to JSpecify mode Open

jspecify

Difficulty 5/5 Over a week Newbie friendliness 25/100

uber/NullAway#1360 · Opened Dec 2, 2025
Feature Request: Allow Supplier<@NonNull Foo> -> Supplier<@Nullable Foo> Open

enhancement

Difficulty 5/5 Over a week Newbie friendliness 35/100

uber/NullAway#1356 · 2 comments · 1 reaction · Opened Nov 27, 2025
Calling enum's @NullMarked override of @Nullable method not recognized as @NonNull Open

lowpriority

Difficulty 3/5 1-2 days Newbie friendliness 45/100

uber/NullAway#1343 · 6 comments · 1 reaction · Opened Nov 14, 2025
Treat effectively final variables the same as static final fields when reasoning about "constant" function calls Open

Difficulty 4/5 3-5 days Newbie friendliness 35/100

uber/NullAway#1318 · 3 comments · Opened Oct 26, 2025
JSpecify: restrict instantiation type on constructors like `AtomicReference` Open

jspecify

Difficulty 5/5 Over a week Newbie friendliness 25/100

uber/NullAway#1300 · Opened Sep 20, 2025
Turn on checking of contracts by default Open

Difficulty 5/5 Over a week Newbie friendliness 35/100

uber/NullAway#1296 · 1 reaction · Opened Sep 18, 2025
Generic method inference does not support inferring different nullability for multiple calls to same generic method Open

jspecify

Difficulty 5/5 Over a week Newbie friendliness 45/100

uber/NullAway#1291 · Opened Sep 16, 2025

uber/NullAway

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