refactor: enhance build system and improve code organization (#47)

corybuecker · web-flow · commit afcb96fc1e93 · 2025-07-26T06:20:06.000-05:00
- Add Cargo to dependabot configuration for dependency management
- Extend CI matrix to include ARM Ubuntu (ubuntu-24.04-arm) platform
- Refactor mathematics.rs to separate pure Rust functions from Ruby bindings
- Update build dependencies and add proper build.rs configuration
- Update documentation to reflect Rust implementation instead of C
- Add .ruby-version file for Ruby version management
- Add test case for single element standard deviation edge case
- Clean up .gitignore and add .env to ignored files
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
@@ -8,4 +8,9 @@ updates:
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
-      interval: "weekly"
+      interval: "weekly"
+
+  - package-ecosystem: "cargo"
+    directory: "/"
+    schedule:
+      interval: "weekly"
diff --git a/.github/workflows/branch-protection.yaml b/.github/workflows/branch-protection.yaml
@@ -12,6 +12,7 @@ jobs:
         os:
           - ubuntu-latest
           - macos-latest
+          - ubuntu-24.04-arm
         ruby:
           - 3.2.8
           - 3.3.8
diff --git a/.github/workflows/continuous-delivery.yaml b/.github/workflows/continuous-delivery.yaml
@@ -7,6 +7,7 @@ on:
   push:
     branches:
       - main
+
 concurrency:
   group: continuous-delivery
   cancel-in-progress: true
@@ -19,6 +20,7 @@ jobs:
         os:
           - ubuntu-latest
           - macos-latest
+          - ubuntu-24.04-arm
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
diff --git a/.gitignore b/.gitignore
@@ -57,6 +57,6 @@ build-iPhoneSimulator/
 
 *.bundle
 
-/ext/ruby_native_statistics/target
 /target
 /.rules
+.env
diff --git a/.ruby-version b/.ruby-version
@@ -0,0 +1 @@
+3.4.4
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Gemfile.lock b/Gemfile.lock
@@ -22,6 +22,7 @@ PLATFORMS
 
 DEPENDENCIES
   minitest (~> 5.21)
+  rake (~> 13.0)
   ruby_native_statistics!
 
 BUNDLED WITH
diff --git a/README.md b/README.md
@@ -2,7 +2,7 @@
 
 [![Test status](https://github.com/corybuecker/ruby-native-statistics/workflows/Test%20suite/badge.svg)](https://github.com/corybuecker/ruby-native-statistics/actions)
 
-This is a native extension to Ruby that adds native (C) statistical functions to the Array class. At present the following functions are provided:
+This is a native extension to Ruby that adds native (Rust) statistical functions to the Array class. At present the following functions are provided:
 
 - [Sample Standard Deviation](https://en.wikipedia.org/wiki/Standard_deviation#Corrected_sample_standard_deviation) (stdev, stdevs)
 - [Population Standard Deviation](https://en.wikipedia.org/wiki/Standard_deviation#Uncorrected_sample_standard_deviation) (stdevp)
diff --git a/ext/ruby_native_statistics/Cargo.toml b/ext/ruby_native_statistics/Cargo.toml
@@ -6,9 +6,10 @@ edition = "2024"
 [lib]
 crate-type = ["cdylib"]
 
+[build-dependencies]
+rb-sys-env = "0.2.2"
+
 [dependencies]
-magnus = { version = "0.7.1", features = ["rb-sys"] }
+magnus = { version = "0.7.1" }
+rb-sys = "0.9.116"
 thiserror = "2.0.12"
-
-[build-dependencies]
-rb-sys-env = "0.1"
diff --git a/ext/ruby_native_statistics/build.rs b/ext/ruby_native_statistics/build.rs
@@ -0,0 +1,6 @@
+use rb_sys_env;
+
+pub fn main() -> Result<(), Box<dyn std::error::Error>> {
+    rb_sys_env::activate()?;
+    Ok(())
+}
diff --git a/ext/ruby_native_statistics/src/mathematics.rs b/ext/ruby_native_statistics/src/mathematics.rs
@@ -20,32 +20,22 @@ impl magnus::error::IntoError for MathematicsError {
     }
 }
 
-pub fn mean(rb_self: RArray) -> Result<f64, MathematicsError> {
-    let array = rb_self
-        .to_vec::<f64>()
-        .map_err(|e| MathematicsError::MagnusError(e))?;
-
-    if array.is_empty() {
-        return Err(MathematicsError::EmptyArray);
-    }
-
-    Ok(calculate_mean(&array))
+// Pure Rust mathematical functions
+pub fn calculate_mean(array: &[f64]) -> f64 {
+    let length = array.len() as f64;
+    let sum = array.iter().sum::<f64>();
+    sum / length
 }
 
-pub fn median(rb_self: RArray) -> Result<f64, MathematicsError> {
-    let array = rb_self
-        .to_vec::<f64>()
-        .map_err(|e| MathematicsError::MagnusError(e))?;
-
-    let length = array.len();
-
+pub fn calculate_median(array: &[f64]) -> Result<f64, MathematicsError> {
     if array.is_empty() {
         return Err(MathematicsError::EmptyArray);
     }
 
-    let mut sorted_array = array;
+    let mut sorted_array = array.to_vec();
     sorted_array.sort_by(|a, b| a.total_cmp(b));
 
+    let length = sorted_array.len();
     let array_even_size = (length % 2) == 0;
     let middle = length / 2;
 
@@ -56,8 +46,22 @@ pub fn median(rb_self: RArray) -> Result<f64, MathematicsError> {
     }
 }
 
-fn calculate_mean(array: &[f64]) -> f64 {
-    let length = array.len() as f64;
-    let sum = array.iter().sum::<f64>();
-    sum / length
+pub fn mean(rb_self: RArray) -> Result<f64, MathematicsError> {
+    let array = rb_self
+        .to_vec::<f64>()
+        .map_err(|e| MathematicsError::MagnusError(e))?;
+
+    if array.is_empty() {
+        return Err(MathematicsError::EmptyArray);
+    }
+
+    Ok(calculate_mean(&array))
+}
+
+pub fn median(rb_self: RArray) -> Result<f64, MathematicsError> {
+    let array = rb_self
+        .to_vec::<f64>()
+        .map_err(|e| MathematicsError::MagnusError(e))?;
+
+    calculate_median(&array)
 }
diff --git a/ruby_native_statistics.gemspec b/ruby_native_statistics.gemspec
@@ -35,6 +35,8 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency 'rake-compiler', '~> 1.3'
   spec.add_dependency 'rb_sys', '~> 0.9.91'
+
+  spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency 'minitest', '~> 5.21'
 
   spec.version = RubyNativeStatistics::VERSION
diff --git a/test/dispersion_test.rb b/test/dispersion_test.rb
@@ -31,6 +31,10 @@ def test_sample_standard_deviation
     assert_in_delta 13.65039682, ((1..10).to_a + [-41, 0]).stdev, 0.00001
   end
 
+  def test_sample_standard_deviation_with_single_element
+    assert [1].stdev.nan?
+  end
+
   def test_sample_variance
     assert_in_delta 186.3333333, ((1..10).to_a + [-41, 0]).var, 0.00001
   end
