Staticcheck 2023.1.7 (v0.4.7)

This release fixes some minor issues in Staticcheck’s intermediate representation. Furthermore, it improves the way QF1003 generates suggested fixes, working around constraints in the language server protocol.

The released binaries for this version have been built with Go 1.22 and should no longer panic when checking code targeting Go 1.22.

Staticcheck 2023.1.6 (v0.4.6)

This release fixes the following bugs:

• A crash when using the upcoming Go 1.22 (issue 1442)
• A false positive in SA9005 when embedding basic types (issue 1443)

Staticcheck 2023.1.5 (v0.4.5)

This release fixes the following bug:

• A crash involving methods named _

Staticcheck 2023.1.4 (v0.4.4)

This release adds support for Go 1.21 and fixes the following bugs:

• Three crashes when encountering unnecessarily parenthesized statements (#1393, #1400)
• Unnecessarily high memory usage when analyzing composite literals such as []int{1<<31: 1} (#1393)
• A false positive in S1011 when appending to a dynamic left-hand side (#1399)
• A crash involving generics (#1410)
• A false positive in SA9001 involving control flow statements (#488)
• A false positive in ST1003, complaining about the names of fuzz functions (#1420)

Staticcheck 2023.1.3 (v0.4.3)

This release fixes the following bugs:

• A crash when embedding type aliases of unnamed types (issue 1361)
• A false positive in U1000, claiming that type aliases are unused (issue 1365)
• A bug in the binary formatter that prevented correct merging behavior for some checks (issue 1372)

Staticcheck 2023.1.2 (v0.4.2)

This release fixes a bug that prevented the binary formatter from working (issue 1370).

Staticcheck 2023.1.1 (v0.4.1)

This release fixes a crash, a false positive in U1000 (issue 1360) and improves the way deprecated API is flagged (issue 1318).

When targeting a Go version that is older than the version that deprecated an API, SA1019 will no longer flag the use even if there is already an alternative available in the targeted Go version.

For example, math/rand.Seed has been deprecated in Go 1.20, but an alternative has existed since Go 1.0. In the past, we would flag uses of Seed even if targeting e.g. Go 1.19, to encourage better forwards compatibility. This can lead to unnecessary churn, however, because the correct change may depend on the Go version in use. For example, for Seed before Go 1.20, the alternative is to use a separate instance of math/rand.Rand, whereas in Go 1.20, a possible alternative is to simply drop the call to Seed.

Staticcheck 2023.1 (v0.4.0)

Staticcheck 2023.1 adds support for Go 1.20, brings minor improvements to various checks, and replaces U1000 with a new implementation.

The following checks have been improved:

• The wording of S1001 has been made clearer for cases involving arrays. Furthermore, it no longer suggests using copy when the function has been shadowed.
• S1011 now recognizes index-based loops (issue 881).
• SA1019 no longer flags tests (internal or external) that use deprecated API from the package under test (issue 1285). Furthermore, entire declaration groups (such as groups of constants) can now be marked as deprecated (issue 1313).
• SA4017 now detects more functions, including those in the time package (issue 1353). Additionally, its wording has been made clearer.
• SA5010 no longer gets confused by type assertions involving generic types (issue 1354).
• ST1005 no longer flags errors that start with alpha-numeric acronyms such as P384.
• Improvements to our intermediate representation may allow various checks to find more problems.

Staticcheck now knows about version 2 of the k8s.io/klog package, in particular which functions abort control flow (issue 1307).

In addition to these minor improvements, U1000 has been rewritten from the ground up, operating on a program representation more suited to the task. In practice this means that there will be fewer false positives and more true positives.

Overall, the rewrite fixes at least eight known bugs, both ones that have been a nuisance for a while, as well as ones newly introduced by generics (issue 507, issue 633, issue 810, issue 812, issue 1199, issue 1249, issue 1282, issue 1333).

Staticcheck 2022.1.3 (v0.3.3)

This release addresses the following issues:

• Staticcheck maintains a cache to speed up repeated runs. This cache needs to be pruned regularly to keep its size in check. This is meant to happen automatically, but it hasn’t since Staticcheck 2020.2. This release corrects that (issue 1283.)
• Some type sets containing both bidirectional and unidirectional channels would lead to panics (issue 1304)

Staticcheck 2022.1.2 (v0.3.2)

This release addresses the following false positives, crashes, infinite loops, and performance issues:

• For certain packages that contain tens of thousands of types and methods, such as those generated by ygot, Staticcheck now finishes much faster.
• Several infinite loops when handling recursive type parameters have been fixed
• S1009 no longer mistakes user-defined functions named len for the builtin (issue 1181)
• ST1015 no longer reorders switch statements if their order is significant due to the use of fallthrough (issue 1188)
• SA1013 now detects constants more robustly, avoiding both false negatives and false positives. Furthermore, it makes sure that offending methods implement io.Seeker and doesn’t just rely on the name Seek (issue 1213).
• SA5008 now understands more third-party extensions to json struct tags
• A crash involving functions named _ has been fixed (issue 1268)
• A crash involving slicing type parameters of type string | []byte has been fixed (issue 1270)
• SA1019 now handles imports of deprecated standard library packages in the same way it handles other deprecated API, taking the targeted Go version into consideration (issue 1117)

Additionally it is strongly recommended to use Go 1.18.2 for building Staticcheck, as it fixes further generics-related bugs in the type checker.