chore: add license header to all file + CI GH action check (#1599)

* added licence comment on correctors.py

* added licence comments to various files

* added licence comment on ratio_estimators.py

* added licence comment to various files

* added licence comment to tests/ files

* added licence comment to __init__ module files

* added check on headers as a CI step within github workflows

* fix: fixed debugging output in CI script for checking licence headers

* Moved license-check to separate file

Author: nMaax

.github/workflows/license-check.yml

@@ -0,0 +1,64 @@
+name: License Header Check
+
+on: [pull_request, workflow_dispatch]
+
+defaults:
+  run:
+    shell: bash
+
+jobs:
+  check-license-headers:
+    name: Check License Headers
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        lfs: false
+
+    - name: Check license headers
+      run: |
+          expected_header_1="# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed"
+          expected_header_2="# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>"
+
+          invalid_files=()
+
+          while IFS= read -r file; do
+              file_header_1=$(head -n 1 "$file")
+              file_header_2=$(head -n 2 "$file" | tail -n 1)
+
+              invalid=false
+
+              # Check the first line
+              if [ "$file_header_1" != "$expected_header_1" ]; then
+                  invalid=true
+              fi
+
+              # Check the second line
+              if [ "$file_header_2" != "$expected_header_2" ]; then
+                  invalid=true
+              fi
+
+              # If either line is invalid, add to the list
+              if [ "$invalid" = true ]; then
+                  invalid_files+=("$file")
+              fi
+
+          done < <(find sbi tests -name "*.py" -type f)
+
+          # Report results
+          if [ ${#invalid_files[@]} -ne 0 ]; then
+              echo "❌ Missing or incorrect license headers in the following files:"
+              for file in "${invalid_files[@]}"; do
+                  echo "   $file"
+              done
+              echo "Make sure the following two lines are provided and correctly spelled at the very start of all above listed files"
+              echo "$expected_header_1"
+              echo "$expected_header_2"
+              exit 1
+          else
+              echo "✅ All files have the correct license headers."
+              exit 0
+          fi

sbi/__init__.py

@@ -1 +1,4 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 from sbi.__version__ import __version__  # noqa: F401

sbi/analysis/__init__.py

@@ -1,3 +1,6 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 from sbi.analysis.conditional_density import (
     ConditionedMDN,
     conditional_corrcoeff,

sbi/diagnostics/__init__.py

@@ -1,3 +1,6 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 from sbi.diagnostics.lc2st import LC2ST
 from sbi.diagnostics.misspecification import (
     calc_misspecification_logprob,

sbi/diagnostics/tarp.py

@@ -1,3 +1,6 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 """
 Implementation taken from Lemos et al, 'Sampling-Based Accuracy Testing of
 Posterior Estimators for General Inference' https://arxiv.org/abs/2302.03026

sbi/examples/__init__.py

@@ -1 +1,4 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 from sbi.examples.minimal import flexible, simple

sbi/examples/minimal.py

@@ -1,3 +1,6 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 import torch
 
 from sbi.inference import SNPE, infer, simulate_for_sbi

sbi/inference/__init__.py

@@ -1,3 +1,6 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 from sbi.inference.abc import MCABC, SMCABC
 from sbi.inference.trainers.base import (
     NeuralInference,  # noqa: F401

sbi/inference/abc/__init__.py

@@ -1,3 +1,6 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 from sbi.inference.abc.mcabc import MCABC
 from sbi.inference.abc.smcabc import SMCABC
 

sbi/inference/posteriors/__init__.py

@@ -1,3 +1,6 @@
+# This file is part of sbi, a toolkit for simulation-based inference. sbi is licensed
+# under the Apache License Version 2.0, see <https://www.apache.org/licenses/>
+
 from sbi.inference.posteriors.direct_posterior import DirectPosterior
 from sbi.inference.posteriors.ensemble_posterior import EnsemblePosterior
 from sbi.inference.posteriors.importance_posterior import ImportanceSamplingPosterior