fix: @putout/processor-wasm: rules: apply-nesting: exclude couple

Author: coderaiser

packages/processor-wasm/lib/rules/apply-nesting/fixture/apply-nesting-fix.wast

@@ -2,7 +2,7 @@
   ;; this is simple function that adds a couple of parameters
 
   (func (param $a i32) (param $b i32)
-    (i32.add (get.local $a) (get.local $b))
+    (i32.add (get.local $b) (get.local $a))
   )
   ;; this statement exports the function to the host environment
 

packages/processor-wasm/lib/rules/apply-nesting/fixture/couple-fix.wast

@@ -0,0 +1,15 @@
+(func $Moore (param $upLeft i32) (param $up i32) (param $upRight i32) (param $right i32) (param $downRight i32) (param $down i32) (param $downLeft i32) (param $left i32) (result i32)
+  (local.get $upLeft)
+  (local.get $up)
+  (local.get $upRight)
+  (local.get $right)
+  (local.get $downRight)
+  (local.get $down)
+  (i32.add (local.get $left) (local.get $downLeft))
+  (i32.add)
+  (i32.add)
+  (i32.add)
+  (i32.add)
+  (i32.add)
+  (i32.add)
+)

packages/processor-wasm/lib/rules/apply-nesting/fixture/couple.wast

@@ -0,0 +1,18 @@
+(func $Moore (export "Moore")
+    (param $upLeft i32) (param $up i32) (param $upRight i32)
+    (param $right i32) (param $downRight i32) (param $down i32)
+    (param $downLeft i32) (param $left i32)
+    (result i32)
+    
+    (local.get $upLeft)
+    (local.get $up)
+    (local.get $upRight)
+    (local.get $right)
+    (local.get $downRight)
+    (local.get $down)
+    (local.get $downLeft)
+    (local.get $left)
+    
+    (i32.add) (i32.add) (i32.add) (i32.add)
+    (i32.add) (i32.add) (i32.add)
+)

packages/processor-wasm/lib/rules/apply-nesting/index.js

@@ -1,24 +1,47 @@
+const INSTRUCTIONS = ['add'];
+
 export const report = (path) => {
     const {id, object} = path.node;
     return `Apply nesting for '${object}.${id}'`;
 };
 
 export const fix = (path) => {
-    const {parentPath, parentKey} = path;
-    const body = parentPath.node[parentKey];
+    const body = getBody(path);
     const index = body.indexOf(path.node);
-    const first = body[index - 2];
-    const second = body[index - 1];
 
-    path.node.args = [first, second];
+    path.node.args = getArgs(path);
     body.splice(index - 2, 2);
 };
 
 export const traverse = ({push}) => ({
     Instr(path) {
         const {id, args} = path.node;
 
-        if (id === 'add' && !args.length)
+        if (args.length)
+            return;
+        
+        const prev = getPrevSibling(path);
+        
+        if (INSTRUCTIONS.includes(prev.id))
+            return;
+        
+        if (INSTRUCTIONS.includes(id))
             push(path);
     },
 });
+
+function getArgs(path) {
+    const first = getPrevSibling(path, 1);
+    const second = getPrevSibling(path, 2);
+    
+    return [first, second];
+}
+
+function getPrevSibling(path, index = 1) {
+    const body = getBody(path);
+    const currentIndex = body.indexOf(path.node);
+    
+    return body[currentIndex - index];
+}
+
+const getBody = ({parentPath, parentKey}) => parentPath.node[parentKey];

packages/processor-wasm/lib/rules/apply-nesting/index.spec.js

@@ -21,3 +21,8 @@ test('putout: processor-wasm: apply-nesting: no report: nested', (t) => {
     t.noReport('nested');
     t.end();
 });
+
+test('putout: processor-wasm: apply-nesting: transform: couple', (t) => {
+    t.transform('couple');
+    t.end();
+});

packages/processor-wasm/test/fixture/apply-nesting-fix.wast

@@ -2,7 +2,7 @@
   ;; this is simple function that adds a couple of parameters
 
   (func (param $a i32) (param $b i32)
-    (i32.add (get.local $a) (get.local $b))
+    (i32.add (get.local $b) (get.local $a))
   )
   ;; this statement exports the function to the host environment
 

packages/processor-wasm/test/fixture/set-local-fix.wast

@@ -2,7 +2,7 @@
   ;; this is simple function that adds a couple of parameters
 
   (func $add (param $a i32) (param $b i32) (result i32)
-    (i32.add (local.set $a) (local.set $b))
+    (i32.add (local.set $b) (local.set $a))
   )
   ;; this statement exports the function to the host environment