Fix Javascript Nom

Author: Luni-4

src/metrics/nom.rs

@@ -97,12 +97,26 @@ impl Nom for MozjsCode {
         use Mozjs::*;
 
         match node.object().kind_id().into() {
-            Function | FunctionDeclaration | MethodDefinition => {
+            FunctionDeclaration | MethodDefinition => {
                 stats.functions += 1;
             }
-            GeneratorFunction | GeneratorFunctionDeclaration | ArrowFunction => {
+            GeneratorFunction | GeneratorFunctionDeclaration => {
                 stats.closures += 1;
             }
+            Function | ArrowFunction => {
+                // Consider named functions as functions and unnamed ones as
+                // closures.
+                if count_specific_ancestors!(
+                    node,
+                    VariableDeclarator,
+                    StatementBlock | ReturnStatement
+                ) == 0
+                {
+                    stats.closures += 1;
+                } else {
+                    stats.functions += 1;
+                }
+            }
             _ => {}
         }
     }
@@ -113,12 +127,26 @@ impl Nom for JavascriptCode {
         use Javascript::*;
 
         match node.object().kind_id().into() {
-            Function | FunctionDeclaration | MethodDefinition => {
+            FunctionDeclaration | MethodDefinition => {
                 stats.functions += 1;
             }
-            GeneratorFunction | GeneratorFunctionDeclaration | ArrowFunction => {
+            GeneratorFunction | GeneratorFunctionDeclaration => {
                 stats.closures += 1;
             }
+            Function | ArrowFunction => {
+                // Consider named functions as functions and unnamed ones as
+                // closures.
+                if count_specific_ancestors!(
+                    node,
+                    VariableDeclarator,
+                    StatementBlock | ReturnStatement
+                ) == 0
+                {
+                    stats.closures += 1;
+                } else {
+                    stats.functions += 1;
+                }
+            }
             _ => {}
         }
     }
@@ -129,12 +157,26 @@ impl Nom for TypescriptCode {
         use Typescript::*;
 
         match node.object().kind_id().into() {
-            Function | FunctionDeclaration | MethodDefinition => {
+            FunctionDeclaration | MethodDefinition => {
                 stats.functions += 1;
             }
-            GeneratorFunction | GeneratorFunctionDeclaration | ArrowFunction => {
+            GeneratorFunction | GeneratorFunctionDeclaration => {
                 stats.closures += 1;
             }
+            Function | ArrowFunction => {
+                // Consider named functions as functions and unnamed ones as
+                // closures.
+                if count_specific_ancestors!(
+                    node,
+                    VariableDeclarator,
+                    StatementBlock | ReturnStatement
+                ) == 0
+                {
+                    stats.closures += 1;
+                } else {
+                    stats.functions += 1;
+                }
+            }
             _ => {}
         }
     }
@@ -145,12 +187,26 @@ impl Nom for TsxCode {
         use Tsx::*;
 
         match node.object().kind_id().into() {
-            Function | FunctionDeclaration | MethodDefinition => {
+            FunctionDeclaration | MethodDefinition => {
                 stats.functions += 1;
             }
-            GeneratorFunction | GeneratorFunctionDeclaration | ArrowFunction => {
+            GeneratorFunction | GeneratorFunctionDeclaration => {
                 stats.closures += 1;
             }
+            Function | ArrowFunction => {
+                // Consider named functions as functions and unnamed ones as
+                // closures.
+                if count_specific_ancestors!(
+                    node,
+                    VariableDeclarator,
+                    StatementBlock | ReturnStatement
+                ) == 0
+                {
+                    stats.closures += 1;
+                } else {
+                    stats.functions += 1;
+                }
+            }
             _ => {}
         }
     }
@@ -279,20 +335,45 @@ mod tests {
     }
 
     #[test]
-    fn c_nom() {
+    fn javascript_nom() {
         check_metrics!(
-            "int foo();
-
-             int foo() {
-                 return 0;
+            "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.c",
-            CppParser,
+            "foo.js",
+            JavascriptParser,
             nom,
             [
-                (functions, 1, usize),
-                (closures, 0, usize),
-                (total, 1, usize)
+                (functions, 3, usize), // f, foo, bar
+                (closures, 1, usize),  // return function ()
+                (total, 4, usize)
+            ]
+        );
+    }
+
+    #[test]
+    fn javascript_nom_arrow() {
+        check_metrics!(
+            "var materials = [\"Hydrogen\"];
+             materials.map(material => material.length);
+             let add = (a, b)  => a + b;",
+            "foo.js",
+            JavascriptParser,
+            nom,
+            [
+                (functions, 1, usize), // add
+                (closures, 1, usize),  // materials.map
+                (total, 2, usize)
             ]
         );
     }