src/metrics/nom.rs

use serde::Serialize;
use serde::ser::{SerializeStruct, Serializer};
use std::fmt;

use crate::checker::Checker;
use crate::macros::implement_metric_trait;

use crate::*;

/// The `Nom` metric suite.
#[derive(Clone, Debug)]
pub struct Stats {
    functions: usize,
    closures: usize,
    functions_sum: usize,
    closures_sum: usize,
    functions_min: usize,
    functions_max: usize,
    closures_min: usize,
    closures_max: usize,
    space_count: usize,
}

impl Default for Stats {
    fn default() -> Self {
        Self {
            functions: 0,
            closures: 0,
            functions_sum: 0,
            closures_sum: 0,
            functions_min: usize::MAX,
            functions_max: 0,
            closures_min: usize::MAX,
            closures_max: 0,
            space_count: 1,
        }
    }
}

impl Serialize for Stats {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        let mut st = serializer.serialize_struct("nom", 10)?;
        st.serialize_field("functions", &self.functions_sum())?;
        st.serialize_field("closures", &self.closures_sum())?;
        st.serialize_field("functions_average", &self.functions_average())?;
        st.serialize_field("closures_average", &self.closures_average())?;
        st.serialize_field("total", &self.total())?;
        st.serialize_field("average", &self.average())?;
        st.serialize_field("functions_min", &self.functions_min())?;
        st.serialize_field("functions_max", &self.functions_max())?;
        st.serialize_field("closures_min", &self.closures_min())?;
        st.serialize_field("closures_max", &self.closures_max())?;
        st.end()
    }
}

impl fmt::Display for Stats {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(
            f,
            "functions: {}, \
             closures: {}, \
             functions_average: {}, \
             closures_average: {}, \
             total: {} \
             average: {} \
             functions_min: {} \
             functions_max: {} \
             closures_min: {} \
             closures_max: {}",
            self.functions_sum(),
            self.closures_sum(),
            self.functions_average(),
            self.closures_average(),
            self.total(),
            self.average(),
            self.functions_min(),
            self.functions_max(),
            self.closures_min(),
            self.closures_max(),
        )
    }
}

impl Stats {
    /// Merges a second `Nom` metric suite into the first one
    pub fn merge(&mut self, other: &Stats) {
        self.functions_min = self.functions_min.min(other.functions_min);
        self.functions_max = self.functions_max.max(other.functions_max);
        self.closures_min = self.closures_min.min(other.closures_min);
        self.closures_max = self.closures_max.max(other.closures_max);
        self.functions_sum += other.functions_sum;
        self.closures_sum += other.closures_sum;
        self.space_count += other.space_count;
    }

    /// Counts the number of function definitions in a scope
    #[inline(always)]
    pub fn functions(&self) -> f64 {
        // Only function definitions are considered, not general declarations
        self.functions as f64
    }

    /// Counts the number of closures in a scope
    #[inline(always)]
    pub fn closures(&self) -> f64 {
        self.closures as f64
    }

    /// Return the sum metric for functions
    #[inline(always)]
    pub fn functions_sum(&self) -> f64 {
        // Only function definitions are considered, not general declarations
        self.functions_sum as f64
    }

    /// Return the sum metric for closures
    #[inline(always)]
    pub fn closures_sum(&self) -> f64 {
        self.closures_sum as f64
    }

    /// Returns the average number of function definitions over all spaces
    #[inline(always)]
    pub fn functions_average(&self) -> f64 {
        self.functions_sum() / self.space_count as f64
    }

    /// Returns the average number of closures over all spaces
    #[inline(always)]
    pub fn closures_average(&self) -> f64 {
        self.closures_sum() / self.space_count as f64
    }

    /// Returns the average number of function definitions and closures over all spaces
    #[inline(always)]
    pub fn average(&self) -> f64 {
        self.total() / self.space_count as f64
    }

    /// Counts the number of function definitions in a scope
    #[inline(always)]
    pub fn functions_min(&self) -> f64 {
        // Only function definitions are considered, not general declarations
        self.functions_min as f64
    }

    /// Counts the number of closures in a scope
    #[inline(always)]
    pub fn closures_min(&self) -> f64 {
        self.closures_min as f64
    }
    /// Counts the number of function definitions in a scope
    #[inline(always)]
    pub fn functions_max(&self) -> f64 {
        // Only function definitions are considered, not general declarations
        self.functions_max as f64
    }

    /// Counts the number of closures in a scope
    #[inline(always)]
    pub fn closures_max(&self) -> f64 {
        self.closures_max as f64
    }
    /// Returns the total number of function definitions and
    /// closures in a scope
    #[inline(always)]
    pub fn total(&self) -> f64 {
        self.functions_sum() + self.closures_sum()
    }
    #[inline(always)]
    pub(crate) fn compute_sum(&mut self) {
        self.functions_sum += self.functions;
        self.closures_sum += self.closures;
    }
    #[inline(always)]
    pub(crate) fn compute_minmax(&mut self) {
        self.functions_min = self.functions_min.min(self.functions);
        self.functions_max = self.functions_max.max(self.functions);
        self.closures_min = self.closures_min.min(self.closures);
        self.closures_max = self.closures_max.max(self.closures);
        self.compute_sum();
    }
}

pub trait Nom
where
    Self: Checker,
{
    fn compute(node: &Node, stats: &mut Stats) {
        if Self::is_func(node) {
            stats.functions += 1;
            return;
        }
        if Self::is_closure(node) {
            stats.closures += 1;
        }
    }
}

implement_metric_trait!(
    [Nom],
    PythonCode,
    MozjsCode,
    JavascriptCode,
    TypescriptCode,
    TsxCode,
    CppCode,
    RustCode,
    PreprocCode,
    CcommentCode,
    JavaCode,
    KotlinCode
);

#[cfg(test)]
mod tests {
    use crate::tools::check_metrics;

    use super::*;

    #[test]
    fn python_nom() {
        check_metrics::<PythonParser>(
            "def a():
                 pass
             def b():
                 pass
             def c():
                 pass
             x = lambda a : a + 42",
            "foo.py",
            |metric| {
                // Number of spaces = 4
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 3.0,
                      "closures": 1.0,
                      "functions_average": 0.75,
                      "closures_average": 0.25,
                      "total": 4.0,
                      "average": 1.0,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn rust_nom() {
        check_metrics::<RustParser>(
            "mod A { fn foo() {}}
             mod B { fn foo() {}}
             let closure = |i: i32| -> i32 { i + 42 };",
            "foo.rs",
            |metric| {
                // Number of spaces = 4
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 2.0,
                      "closures": 1.0,
                      "functions_average": 0.5,
                      "closures_average": 0.25,
                      "total": 3.0,
                      "average": 0.75,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn c_nom() {
        check_metrics::<CppParser>(
            "int foo();

             int foo() {
                 return 0;
             }",
            "foo.c",
            |metric| {
                // Number of spaces = 2
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 1.0,
                      "closures": 0.0,
                      "functions_average": 0.5,
                      "closures_average": 0.0,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 0.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn cpp_nom() {
        check_metrics::<CppParser>(
            "struct A {
                 void foo(int) {}
                 void foo(double) {}
             };
             int b = [](int x) -> int { return x + 42; };",
            "foo.cpp",
            |metric| {
                // Number of spaces = 4
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 2.0,
                      "closures": 1.0,
                      "functions_average": 0.5,
                      "closures_average": 0.25,
                      "total": 3.0,
                      "average": 0.75,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_nom() {
        check_metrics::<JavascriptParser>(
            "function f(a, b) {
                 function foo(a) {
                     return a;
                 }
                 var bar = (function () {
                     var counter = 0;
                     return function () {
                         counter += 1;
                         return counter
                     }
                 })();
                 return bar(foo(a), a);
             }",
            "foo.js",
            |metric| {
                // Number of spaces = 5
                // functions: f, foo, bar
                // closures:  return function ()
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 3.0,
                      "closures": 1.0,
                      "functions_average": 0.6,
                      "closures_average": 0.2,
                      "total": 4.0,
                      "average": 0.8,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_call_nom() {
        check_metrics::<JavascriptParser>(
            "add_task(async function test_safe_mode() {
                 gAppInfo.inSafeMode = true;
             });",
            "foo.js",
            |metric| {
                // Number of spaces = 2
                // functions: test_safe_mode
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 1.0,
                      "closures": 0.0,
                      "functions_average": 0.5,
                      "closures_average": 0.0,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 0.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_assignment_nom() {
        check_metrics::<JavascriptParser>(
            "AnimationTest.prototype.enableDisplay = function(element) {};",
            "foo.js",
            |metric| {
                // Number of spaces = 2
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 1.0,
                      "closures": 0.0,
                      "functions_average": 0.5,
                      "closures_average": 0.0,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 0.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_labeled_nom() {
        check_metrics::<JavascriptParser>(
            "toJSON: function() {
                 return this.inspect(true);
             }",
            "foo.js",
            |metric| {
                // Number of spaces = 2
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 1.0,
                      "closures": 0.0,
                      "functions_average": 0.5,
                      "closures_average": 0.0,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 0.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_labeled_arrow_nom() {
        check_metrics::<JavascriptParser>(
            "const dimConverters = {
                pt: x => x,
             };",
            "foo.js",
            |metric| {
                // Number of spaces = 2
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 1.0,
                      "closures": 0.0,
                      "functions_average": 0.5,
                      "closures_average": 0.0,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 0.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_pair_nom() {
        check_metrics::<JavascriptParser>(
            "return {
                 initialize: function(object) {
                     this._object = object.toObject();
                 },
             }",
            "foo.js",
            |metric| {
                // Number of spaces = 2
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 1.0,
                      "closures": 0.0,
                      "functions_average": 0.5,
                      "closures_average": 0.0,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 0.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_unnamed_nom() {
        check_metrics::<JavascriptParser>(
            "Ajax.getTransport = Try.these(
                 function() {
                     return function(){ return new XMLHttpRequest()}
                 }
             );",
            "foo.js",
            |metric| {
                // Number of spaces = 3
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 0.0,
                      "closures": 2.0,
                      "functions_average": 0.0,
                      "closures_average": 0.6666666666666666,
                      "total": 2.0,
                      "average": 0.6666666666666666,
                      "functions_min": 0.0,
                      "functions_max": 0.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_arrow_nom() {
        check_metrics::<JavascriptParser>(
            "var materials = [\"Hydrogen\"];
             materials.map(material => material.length);
             let add = (a, b)  => a + b;",
            "foo.js",
            |metric| {
                // Number of spaces = 3
                // Functions: add
                // Closures: material.map
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 1.0,
                      "closures": 1.0,
                      "functions_average": 0.3333333333333333,
                      "closures_average": 0.3333333333333333,
                      "total": 2.0,
                      "average": 0.6666666666666666,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_arrow_assignment_nom() {
        check_metrics::<JavascriptParser>("sink.onPull = () => { };", "foo.js", |metric| {
            // Number of spaces = 2
            insta::assert_json_snapshot!(
                metric.nom,
                @r###"
                    {
                      "functions": 1.0,
                      "closures": 0.0,
                      "functions_average": 0.5,
                      "closures_average": 0.0,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 0.0
                    }"###
            );
        });
    }

    #[test]
    fn javascript_arrow_new_nom() {
        check_metrics::<JavascriptParser>(
            "const response = new Promise(resolve => channel.port1.onmessage = resolve);",
            "foo.js",
            |metric| {
                // Number of spaces = 2
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 0.0,
                      "closures": 1.0,
                      "functions_average": 0.0,
                      "closures_average": 0.5,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 0.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn javascript_arrow_call_nom() {
        check_metrics::<JavascriptParser>(
            "let notDisabled = TestUtils.waitForCondition(
                 () => !backbutton.hasAttribute(\"disabled\")
             );",
            "foo.js",
            |metric| {
                // Number of spaces = 2
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 0.0,
                      "closures": 1.0,
                      "functions_average": 0.0,
                      "closures_average": 0.5,
                      "total": 1.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 0.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn java_nom() {
        check_metrics::<JavaParser>(
            "class A {
                public void foo(){
                    return;
                }
                public void bar(){
                    return;
                }
            }",
            "foo.java",
            |metric| {
                // Number of spaces = 4
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 2.0,
                      "closures": 0.0,
                      "functions_average": 0.5,
                      "closures_average": 0.0,
                      "total": 2.0,
                      "average": 0.5,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 0.0
                    }"###
                );
            },
        );
    }

    #[test]
    fn java_closure_nom() {
        check_metrics::<JavaParser>(
            "interface printable{
                void print();
              }

              interface IntFunc {
                int func(int n);
              }

              class Printer implements printable{
                public void print(){System.out.println(\"Hello\");}

                public static void main(String args[]){
                  Printer  obj = new Printer();
                  obj.print();
                  IntFunc meaning = (i) -> i + 42;
                  int i = meaning.func(1);
                }
              }",
            "foo.java",
            |metric| {
                // Number of spaces = 8
                insta::assert_json_snapshot!(
                    metric.nom,
                    @r###"
                    {
                      "functions": 4.0,
                      "closures": 1.0,
                      "functions_average": 0.5,
                      "closures_average": 0.125,
                      "total": 5.0,
                      "average": 0.625,
                      "functions_min": 0.0,
                      "functions_max": 1.0,
                      "closures_min": 0.0,
                      "closures_max": 1.0
                    }"###
                );
            },
        );
    }
}