chore: set up pre-commit for formatting

.buildkite/pipeline.yml

@@ -8,4 +8,4 @@ steps:
     agents:
       queue: "juliagpu"
       cuda: "*"
-    timeout_in_minutes: 60
+    timeout_in_minutes: 60

.github/workflows/CompatHelper.yml

@@ -42,4 +42,4 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           COMPATHELPER_PRIV: ${{ secrets.DOCUMENTER_KEY }}
-          # COMPATHELPER_PRIV: ${{ secrets.COMPATHELPER_PRIV }}
+          # COMPATHELPER_PRIV: ${{ secrets.COMPATHELPER_PRIV }}

.github/workflows/Documentation.yml

@@ -15,7 +15,7 @@ concurrency:
   cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
 
 jobs:
-  
+
   docs:
     name: ${{ matrix.pkg.shortcut }}
     runs-on: ubuntu-latest
@@ -33,7 +33,7 @@ jobs:
           - name: DifferentiationInterfaceTest
             shortcut: DIT
             dir: './DifferentiationInterfaceTest'
-    
+
     steps:
       - uses: actions/checkout@v4
       - uses: julia-actions/setup-julia@v2

.github/workflows/PreCommit.yml

@@ -0,0 +1,27 @@
+name: Pre-Commit
+
+# needed to allow julia-actions/cache to delete old caches that it has created
+permissions:
+  actions: write
+  contents: read
+
+on:
+  push:
+    branches:
+      - main
+    tags: ["*"]
+  pull_request:
+    types: [opened, reopened, synchronize, ready_for_review]
+  workflow_dispatch:
+
+jobs:
+  pre-commit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@v2
+      - uses: julia-actions/cache@v2
+      - run: julia -e 'using Pkg; Pkg.add("JuliaFormatter")'
+      - uses: astral-sh/setup-uv@v6
+      - run: uv tool install pre-commit
+      - run: pre-commit run --all-files --show-diff-on-failure --color always

.github/workflows/Register.yml

@@ -13,4 +13,4 @@ jobs:
     steps:
       - uses: julia-actions/RegisterAction@latest
         with:
-          token: ${{ secrets.GITHUB_TOKEN }}
+          token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/TagBot.yml

@@ -36,4 +36,4 @@ jobs:
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           ssh: ${{ secrets.DOCUMENTER_KEY }}
-          subdir: DifferentiationInterfaceTest
+          subdir: DifferentiationInterfaceTest

.gitignore

@@ -11,4 +11,4 @@
 *.csv
 
 playground.jl
-.vscode
+.vscode

.pre-commit-config.yaml

@@ -0,0 +1,15 @@
+repos:
+-   repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v3.2.0
+    hooks:
+    -   id: trailing-whitespace
+    -   id: end-of-file-fixer
+    -   id: check-yaml
+    -   id: check-added-large-files
+    -   id: check-merge-conflict
+    -   id: no-commit-to-branch
+-   repo: "https://github.com/domluna/JuliaFormatter.jl"
+    rev: "v2.1.6"  # or whatever the desired release is
+    hooks:
+    -   id: "julia-formatter"
+fail_fast: true

CONTRIBUTING.md

@@ -9,5 +9,7 @@ _Only the two maintainers are allowed to approve and merge pull requests._
 Feel free to ping them if they do not answer within a week or so.
 
 Apart from the conditions above, this repository follows the [ColPrac](https://github.com/SciML/ColPrac) best practices and [Conventional Commits](https://www.conventionalcommits.org/en/).
-Its code is formatted using [JuliaFormatter.jl](https://github.com/domluna/JuliaFormatter.jl) with [BlueStyle](https://github.com/JuliaDiff/BlueStyle) -- please format any modified code before opening a pull request, otherwise CI will fail.
+Its code is formatted using [JuliaFormatter.jl](https://github.com/domluna/JuliaFormatter.jl) with [BlueStyle](https://github.com/JuliaDiff/BlueStyle).
+As part of continuous integration, a set of formal tests is run using [pre-commit](https://pre-commit.com/).
+We invite you to install pre-commit so that these checks are performed locally before you open or update a pull request.
 You can refer to the [dev guide](https://juliadiff.org/DifferentiationInterface.jl/DifferentiationInterface/dev/dev_guide/) for details on the package structure and the testing pipeline.

DifferentiationInterface/CHANGELOG.md

@@ -93,4 +93,4 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#790]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/790
 [#788]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/788
 [#782]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/782
-[#768]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/768
+[#768]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/768

DifferentiationInterface/Project.toml

@@ -75,7 +75,6 @@ GPUArraysCore = "0.2"
 GTPSA = "1.4.0"
 JET = "0.9"
 JLArrays = "0.2.0"
-JuliaFormatter = "1,2"
 LinearAlgebra = "1"
 Mooncake = "0.4.147"
 Pkg = "1"
@@ -110,7 +109,6 @@ ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 GTPSA = "b27dd330-f138-47c5-815b-40db9dd9b6e8"
 JET = "c3a54625-cd67-489e-a8e7-0a5a0ff4e31b"
 JLArrays = "27aeb0d3-9eb9-45fb-866b-73c2ecf80fcb"
-JuliaFormatter = "98e50ef6-434e-11e9-1051-2b60c6c9e899"
 Mooncake = "da2b9cff-9c12-43a0-ae48-6db2b0edb7d6"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
 PolyesterForwardDiff = "98d1487c-24ca-40b6-b7ab-df2af84e126b"
@@ -136,7 +134,6 @@ test = [
     "ExplicitImports",
     "JET",
     "JLArrays",
-    "JuliaFormatter",
     "Pkg",
     "Random",
     "SparseArrays",

DifferentiationInterface/README.md

@@ -73,7 +73,7 @@ Pkg.add(
 
 ```julia
 using DifferentiationInterface
-import ForwardDiff, Enzyme, Zygote  # AD backends you want to use 
+import ForwardDiff, Enzyme, Zygote  # AD backends you want to use
 
 f(x) = sum(abs2, x)
 
@@ -97,23 +97,23 @@ You can use the provided [`CITATION.cff`](https://github.com/JuliaDiff/Different
 
 ```bibtex
 @misc{dalle2025commoninterfaceautomaticdifferentiation,
-      title={A Common Interface for Automatic Differentiation}, 
+      title={A Common Interface for Automatic Differentiation},
       author={Guillaume Dalle and Adrian Hill},
       year={2025},
       eprint={2505.05542},
       archivePrefix={arXiv},
       primaryClass={cs.MS},
-      url={https://arxiv.org/abs/2505.05542}, 
+      url={https://arxiv.org/abs/2505.05542},
 }
 
 @misc{schäfer2022abstractdifferentiationjlbackendagnosticdifferentiableprogramming,
-      title={AbstractDifferentiation.jl: Backend-Agnostic Differentiable Programming in Julia}, 
+      title={AbstractDifferentiation.jl: Backend-Agnostic Differentiable Programming in Julia},
       author={Frank Schäfer and Mohamed Tarek and Lyndon White and Chris Rackauckas},
       year={2022},
       eprint={2109.12449},
       archivePrefix={arXiv},
       primaryClass={cs.MS},
-      url={https://arxiv.org/abs/2109.12449}, 
+      url={https://arxiv.org/abs/2109.12449},
 }
 ```
 

DifferentiationInterface/docs/src/assets/logo.jl

@@ -47,7 +47,7 @@ end
 
 # ╔═╡ 69d0fa4d-2585-42a0-981f-99d43f7e2c1f
 md"## Creating Favicons
-Using Imagemagick, run 
+Using Imagemagick, run
 ```bash
 convert -background transparent logo.svg -define icon:auto-resize=256,128,48,32,16 favicon.ico
 ```

DifferentiationInterface/docs/src/faq/differentiability.md

@@ -51,7 +51,7 @@ In some situations, manually writing overloads for `x::Dual` or `x::AbstractArra
 ### ReverseDiff
 
 [ReverseDiff.jl](https://github.com/JuliaDiff/ReverseDiff.jl) relies on operator overloading for scalars, but also for arrays.
-The relevant types are called `TrackedReal` and `TrackedArray`, they have a set of [limitations](https://juliadiff.org/ReverseDiff.jl/stable/limits/) very similar to that of ForwardDiff.jl's `Dual` and will cause similar errors. 
+The relevant types are called `TrackedReal` and `TrackedArray`, they have a set of [limitations](https://juliadiff.org/ReverseDiff.jl/stable/limits/) very similar to that of ForwardDiff.jl's `Dual` and will cause similar errors.
 
 ### Symbolic backends
 
@@ -112,4 +112,4 @@ There are, however, translation utilities:
 
 Also note the existence of [`DifferentiationInterface.DifferentiateWith`](@ref), which allows the user to wrap a function that should be differentiated with a specific backend.
 
-Right now, it only targets [ForwardDiff.jl](https://github.com/JuliaDiff/ForwardDiff.jl), [Mooncake.jl](), [ChainRules.jl](https://juliadiff.org/ChainRulesCore.jl/stable/)-compatible backends (e.g., [Zygote.jl](https://github.com/FluxML/Zygote.jl)), but PRs are welcome to define Enzyme.jl rules for this object.
+Right now, it only targets [ForwardDiff.jl](https://github.com/JuliaDiff/ForwardDiff.jl), [Mooncake.jl](), [ChainRules.jl](https://juliadiff.org/ChainRulesCore.jl/stable/)-compatible backends (e.g., [Zygote.jl](https://github.com/FluxML/Zygote.jl)), but PRs are welcome to define Enzyme.jl rules for this object.

DifferentiationInterface/ext/DifferentiationInterfaceGTPSAExt/onearg.jl

@@ -114,7 +114,7 @@ struct GTPSAOneArgGradientPrep{SIG,X} <: DI.GradientPrep{SIG}
     xt::X
 end
 
-# Unlike JVP, this requires us to use all variables 
+# Unlike JVP, this requires us to use all variables
 function DI.prepare_gradient_nokwarg(
     strict::Val, f, backend::AutoGTPSA{D}, x, contexts::Vararg{DI.Constant,C}
 ) where {D,C}
@@ -197,7 +197,7 @@ struct GTPSAOneArgJacobianPrep{SIG,X} <: DI.JacobianPrep{SIG}
     xt::X
 end
 
-# To materialize the entire Jacobian we use all variables 
+# To materialize the entire Jacobian we use all variables
 function DI.prepare_jacobian_nokwarg(
     strict::Val, f, backend::AutoGTPSA{D}, x, contexts::Vararg{DI.Constant,C}
 ) where {D,C}
@@ -406,7 +406,7 @@ function DI.value_derivative_and_second_derivative!(
 end
 
 ## Hessian
-# Stores allocated array of TPS and an array for the monomial coefficient 
+# Stores allocated array of TPS and an array for the monomial coefficient
 # indexing in GTPSA.cycle! (which is used if a Descriptor is specified)
 struct GTPSAOneArgHessianPrep{SIG,X,M} <: DI.HessianPrep{SIG}
     _sig::Val{SIG}
@@ -424,14 +424,14 @@ function DI.prepare_hessian_nokwarg(
     else
         nn = length(x)
         d = Descriptor(nn, 2)
-        # If all variables/variable+parameters have truncation order > 2, then 
+        # If all variables/variable+parameters have truncation order > 2, then
         # the indexing is known beforehand and we can do it (very slightly) faster
         m = nothing
     end
     xt = similar(x, TPS{promote_type(eltype(x), Float64)})
 
     # xt and x have same indexing because of similar
-    # Setting the first derivatives must be 1-based 
+    # Setting the first derivatives must be 1-based
     # linear with the variables.
     j = 1
     for i in eachindex(xt)

DifferentiationInterface/test/Back/GTPSA/test.jl

@@ -27,7 +27,7 @@ test_differentiation(
 d1 = GTPSA.Descriptor(20, 2) # 20 variables to 2nd order
 test_differentiation(AutoGTPSA(d1); type_stability=:full, logging=LOGGING);
 
-# Test with Descriptor using varying orders 
+# Test with Descriptor using varying orders
 vos = 2 * ones(Int, 20)
 vos[1] = 3
 d2 = GTPSA.Descriptor(vos, 3)

DifferentiationInterface/test/Core/Internals/_formalities.jl

@@ -4,7 +4,6 @@ using Aqua: Aqua
 using DifferentiationInterface
 using ExplicitImports
 using JET: JET
-using JuliaFormatter: JuliaFormatter
 using Test
 using SparseMatrixColorings
 using SparseArrays
@@ -17,10 +16,6 @@ end
     JET.test_package(DifferentiationInterface; target_defined_modules=true)
 end
 
-@testset "JuliaFormatter" begin
-    @test JuliaFormatter.format(DifferentiationInterface; verbose=false, overwrite=false)
-end
-
 @testset "Documentation" begin
     if VERSION >= v"1.11"
         @test isempty(Docs.undocumented_names(DifferentiationInterface))

DifferentiationInterfaceTest/CHANGELOG.md

@@ -38,4 +38,4 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#786]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/786
 [#749]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/749
 [#748]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/748
-[#745]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/745
+[#745]: https://github.com/JuliaDiff/DifferentiationInterface.jl/pull/745

DifferentiationInterfaceTest/Project.toml

@@ -59,7 +59,6 @@ ForwardDiff = "0.10.36,1"
 Functors = "0.4, 0.5"
 JET = "0.4 - 0.8, 0.9"
 JLArrays = "0.1, 0.2"
-JuliaFormatter = "1,2"
 LinearAlgebra = "1"
 Lux = "1.1.0"
 LuxTestUtils = "1.3.1"
@@ -88,7 +87,6 @@ Flux = "587475ba-b771-5e3f-ad9e-33799f191a9c"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 JET = "c3a54625-cd67-489e-a8e7-0a5a0ff4e31b"
 JLArrays = "27aeb0d3-9eb9-45fb-866b-73c2ecf80fcb"
-JuliaFormatter = "98e50ef6-434e-11e9-1051-2b60c6c9e899"
 Lux = "b2108857-7c20-44ae-9111-449ecde12c47"
 LuxTestUtils = "ac9de150-d08f-4546-94fb-7472b5760531"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
@@ -114,7 +112,6 @@ test = [
     "ForwardDiff",
     "JET",
     "JLArrays",
-    "JuliaFormatter",
     "Pkg",
     "Random",
     "SparseArrays",

DifferentiationInterfaceTest/README.md

@@ -47,7 +47,7 @@ Pkg.add(
     url="https://github.com/JuliaDiff/DifferentiationInterface.jl",
     subdir="DifferentiationInterface"
 )
-    
+
 Pkg.add(
     url="https://github.com/JuliaDiff/DifferentiationInterface.jl",
     subdir="DifferentiationInterfaceTest"

DifferentiationInterfaceTest/test/formalities.jl

@@ -3,18 +3,12 @@ using DifferentiationInterfaceTest
 using Aqua: Aqua
 using ExplicitImports
 using JET: JET
-using JuliaFormatter: JuliaFormatter
 using SparseMatrixColorings: SparseMatrixColorings
 using Test
 
 @testset "Aqua" begin
     Aqua.test_all(DifferentiationInterfaceTest; ambiguities=false, undocumented_names=true)
 end
-@testset "JuliaFormatter" begin
-    @test JuliaFormatter.format(
-        DifferentiationInterfaceTest; verbose=false, overwrite=false
-    )
-end
 @testset verbose = true "JET" begin
     JET.test_package(DifferentiationInterfaceTest; target_defined_modules=true)
 end