perf(core): generate arrow functions for pure function calls (#51668)

Reworks the pure functions to use arrow functions with an implicit return instead of function expressions. This allows us to shave off some bytes for each pure function, because we can avoid some of the syntax.

PR Close #51668

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/array_literals_null_vs_empty.js

@@ -1,6 +1,6 @@
-const $c0$ = function () { return { foo: null }; };
-const $c1$ = function () { return []; };
-const $c2$ = function (a0) { return { foo: a0 }; };
+const $c0$ = () => ({ foo: null });
+const $c1$ = () => [];
+const $c2$ = a0 => ({ foo: a0 });
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/constant_array_literals.js

@@ -1,5 +1,5 @@
-const $c0$ = function () { return []; };
-const $c1$ = function () { return [0, 1, 2]; };
+const $c0$ = () => [];
+const $c1$ = () => [0, 1, 2];
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/constant_object_literals.js

@@ -1,5 +1,5 @@
-const $c0$ = function () { return {}; };
-const $c1$ = function () { return { a: 1, b: 2 }; };
+const $c0$ = () => ({});
+const $c1$ = () => ({ a: 1, b: 2 });
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/object_literals_null_vs_empty.js

@@ -1,6 +1,6 @@
-const $c0$ = function () { return { foo: null }; };
-const $c1$ = function () { return {}; };
-const $c2$ = function (a0) { return { foo: a0 }; };
+const $c0$ = () => ({ foo: null });
+const $c1$ = () => ({});
+const $c2$ = a0 => ({ foo: a0 });
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/object_literals_null_vs_function.js

@@ -1,5 +1,5 @@
-const $c0$ = function () { return { foo: null }; };
-const $c1$ = function (a0) { return { foo: a0 }; };
+const $c0$ = () => ({ foo: null });
+const $c1$ = a0 => ({ foo: a0 });
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/pipes/pipes_my_app_def.js

@@ -1,6 +1,4 @@
-const $c0$ = function ($a0$) {
-  return [$a0$, 1, 2, 3, 4, 5];
-};
+const $c0$ = $a0$ => [$a0$, 1, 2, 3, 4, 5];
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/value_composition/array_literals.js

@@ -1,4 +1,4 @@
-const $e0_ff$ = function ($v$) { return ["Nancy", $v$]; };
+const $e0_ff$ = $v$ => ["Nancy", $v$];
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/value_composition/array_literals_many.js

@@ -1,6 +1,4 @@
-const $e0_ff$ = function ($v0$, $v1$, $v2$, $v3$, $v4$, $v5$, $v6$, $v7$, $v8$) {
-  return ["start-", $v0$, $v1$, $v2$, $v3$, $v4$, "-middle-", $v5$, $v6$, $v7$, $v8$, "-end"];
-}
+const $e0_ff$ = ($v0$, $v1$, $v2$, $v3$, $v4$, $v5$, $v6$, $v7$, $v8$) => ["start-", $v0$, $v1$, $v2$, $v3$, $v4$, "-middle-", $v5$, $v6$, $v7$, $v8$, "-end"];
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/value_composition/literal_nested_expression.js

@@ -1,7 +1,7 @@
-const $c0$ = function () { return {opacity: 0, duration: 0}; };
-const $e0_ff$ = function ($v$) { return {opacity: 1, duration: $v$}; };
-const $e0_ff_1$ = function ($v1$, $v2$) { return [$v1$, $v2$]; };
-const $e0_ff_2$ = function ($v1$, $v2$) { return {animation: $v1$, actions: $v2$}; };
+const $c0$ = () => ({opacity: 0, duration: 0});
+const $e0_ff$ = $v$ => ({opacity: 1, duration: $v$});
+const $e0_ff_1$ = ($v1$, $v2$) => [$v1$, $v2$];
+const $e0_ff_2$ = ($v1$, $v2$) => ({animation: $v1$, actions: $v2$});
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/components_and_directives/value_composition/object_literals.js

@@ -1,4 +1,4 @@
-const $e0_ff$ = function ($v$) { return {"duration": 500, animation: $v$}; };
+const $e0_ff$ = $v$ => ({"duration": 500, animation: $v$});
 // ...
 MyApp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: MyApp,

packages/compiler-cli/test/compliance/test_cases/r3_compiler_compliance/elements/host_binding_pure_functions.js

@@ -1,6 +1,6 @@
-const $_c0$ = function (a0, a1) { return { collapsedHeight: a0, expandedHeight: a1 }; };
-const $_c1$ = function (a0, a1) { return { value: a0, params: a1 }; };
-const $_c2$ = function (a0, a1) { return { collapsedWidth: a0, expandedWidth: a1 }; };
+const $_c0$ = (a0, a1) => ({ collapsedHeight: a0, expandedHeight: a1 });
+const $_c1$ = (a0, a1) => ({ value: a0, params: a1 });
+const $_c2$ = (a0, a1) => ({ collapsedWidth: a0, expandedWidth: a1 });
 …
 hostVars: 14,
 hostBindings: function MyComponent_HostBindings(rf, ctx) {

packages/compiler-cli/test/compliance/test_cases/r3_view_compiler_bindings/host_bindings/host_bindings_with_pure_functions.js

@@ -1,5 +1,5 @@
 
-const $ff$ = function ($v$) { return ["red", $v$]; };
+const $ff$ = $v$ => ["red", $v$];
 …
 HostBindingComp.ɵcmp = /*@__PURE__*/ $r3$.ɵɵdefineComponent({
   type: HostBindingComp,

packages/compiler/src/constant_pool.ts

@@ -222,7 +222,7 @@ export class ConstantPool {
       const parameters =
           resultExpressions.filter(isVariable).map(e => new o.FnParam(e.name!, o.DYNAMIC_TYPE));
       const pureFunctionDeclaration =
-          o.fn(parameters, [new o.ReturnStatement(resultMap(resultExpressions))], o.INFERRED_TYPE);
+          o.arrowFn(parameters, resultMap(resultExpressions), o.INFERRED_TYPE);
       const name = this.freshName();
       this.statements.push(o.variable(name)
                                .set(pureFunctionDeclaration)