[8.6] [@kbn/handlebars] Code cleanup (elastic#147425) (elastic#147789)

# Backport

This will backport the following commits from `main` to `8.6`:
- [[@kbn/handlebars] Code cleanup
(elastic#147425)](elastic#147425)

<!--- Backport version: 8.9.7 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Thomas
Watson","email":"watson@elastic.co"},"sourceCommit":{"committedDate":"2022-12-19T17:24:26Z","message":"[@kbn/handlebars]
Code cleanup
(elastic#147425)","sha":"b00a2643cd7a2980902ee693d67cc6b801daacab","branchLabelMapping":{"^v8.7.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["release_note:skip","backport:prev-minor","v8.7.0"],"number":147425,"url":"elastic#147425
Code cleanup
(elastic#147425)","sha":"b00a2643cd7a2980902ee693d67cc6b801daacab"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v8.7.0","labelRegex":"^v8.7.0$","isSourceBranch":true,"state":"MERGED","url":"elastic#147425
Code cleanup
(elastic#147425)","sha":"b00a2643cd7a2980902ee693d67cc6b801daacab"}}]}]
BACKPORT-->

Co-authored-by: Thomas Watson <watson@elastic.co>

packages/kbn-handlebars/.patches/blocks.patch

@@ -429,30 +429,34 @@
 >       beforeEach(() => {
 >         global.kbnHandlebarsEnv = Handlebars.create();
 >       });
-410c319,323
+410c319,327
 <         handlebarsEnv.registerDecorator('foo', function() {
 ---
+>       afterEach(() => {
+>         global.kbnHandlebarsEnv = null;
+>       });
+> 
 >       it('unregisters', () => {
 >         // @ts-expect-error: Cannot assign to 'decorators' because it is a read-only property.
 >         kbnHandlebarsEnv!.decorators = {};
 > 
 >         kbnHandlebarsEnv!.registerDecorator('foo', function () {
-414,416c327,329
+414,416c331,333
 <         equals(!!handlebarsEnv.decorators.foo, true);
 <         handlebarsEnv.unregisterDecorator('foo');
 <         equals(handlebarsEnv.decorators.foo, undefined);
 ---
 >         expect(!!kbnHandlebarsEnv!.decorators.foo).toEqual(true);
 >         kbnHandlebarsEnv!.unregisterDecorator('foo');
 >         expect(kbnHandlebarsEnv!.decorators.foo).toBeUndefined();
-419,420c332,334
+419,420c336,338
 <       it('allows multiple globals', function() {
 <         handlebarsEnv.decorators = {};
 ---
 >       it('allows multiple globals', () => {
 >         // @ts-expect-error: Cannot assign to 'decorators' because it is a read-only property.
 >         kbnHandlebarsEnv!.decorators = {};
-422,424c336,339
+422,424c340,343
 <         handlebarsEnv.registerDecorator({
 <           foo: function() {},
 <           bar: function() {}
@@ -461,7 +465,7 @@
 >         kbnHandlebarsEnv!.registerDecorator({
 >           foo() {},
 >           bar() {},
-427,432c342,347
+427,432c346,351
 <         equals(!!handlebarsEnv.decorators.foo, true);
 <         equals(!!handlebarsEnv.decorators.bar, true);
 <         handlebarsEnv.unregisterDecorator('foo');
@@ -475,7 +479,7 @@
 >         kbnHandlebarsEnv!.unregisterDecorator('bar');
 >         expect(kbnHandlebarsEnv!.decorators.foo).toBeUndefined();
 >         expect(kbnHandlebarsEnv!.decorators.bar).toBeUndefined();
-435,445c350,356
+435,445c354,360
 <       it('fails with multiple and args', function() {
 <         shouldThrow(
 <           function() {
@@ -495,7 +499,7 @@
 >             {
 >               world() {
 >                 return 'world!';
-447,452c358,364
+447,452c362,368
 <               {}
 <             );
 <           },

packages/kbn-handlebars/.patches/builtins.patch

@@ -668,7 +668,10 @@
 ---
 > 
 >     afterEach(function () {
-578,580c481,484
+575a479,480
+> 
+>       global.kbnHandlebarsEnv = null;
+578,580c483,486
 <     it('should call logger at default level', function() {
 <       var levelArg, logArg;
 <       handlebarsEnv.log = function(level, arg) {
@@ -677,7 +680,7 @@
 >       let levelArg;
 >       let logArg;
 >       kbnHandlebarsEnv!.log = function (level, arg) {
-585,590c489,491
+585,590c491,493
 <       expectTemplate('{{log blah}}')
 <         .withInput({ blah: 'whee' })
 <         .withMessage('log should not display')
@@ -688,7 +691,7 @@
 >       expectTemplate('{{log blah}}').withInput({ blah: 'whee' }).toCompileTo('');
 >       expect(1).toEqual(levelArg);
 >       expect('whee').toEqual(logArg);
-593,595c494,497
+593,595c496,499
 <     it('should call logger at data level', function() {
 <       var levelArg, logArg;
 <       handlebarsEnv.log = function(level, arg) {
@@ -697,20 +700,20 @@
 >       let levelArg;
 >       let logArg;
 >       kbnHandlebarsEnv!.log = function (level, arg) {
-605,606c507,508
+605,606c509,510
 <       equals('03', levelArg);
 <       equals('whee', logArg);
 ---
 >       expect('03').toEqual(levelArg);
 >       expect('whee').toEqual(logArg);
-609,610c511,513
+609,610c513,515
 <     it('should output to info', function() {
 <       var called;
 ---
 >     it('should output to info', function () {
 >       let calls = 0;
 >       const callsExpected = process.env.AST || process.env.EVAL ? 1 : 2;
-612,616c515,521
+612,616c517,523
 <       console.info = function(info) {
 <         equals('whee', info);
 <         called = true;
@@ -724,7 +727,7 @@
 >           console.info = $info;
 >           console.log = $log;
 >         }
-618,622c523,529
+618,622c525,531
 <       console.log = function(log) {
 <         equals('whee', log);
 <         called = true;
@@ -738,22 +741,22 @@
 >           console.info = $info;
 >           console.log = $log;
 >         }
-625,628c532,533
+625,628c534,535
 <       expectTemplate('{{log blah}}')
 <         .withInput({ blah: 'whee' })
 <         .toCompileTo('');
 <       equals(true, called);
 ---
 >       expectTemplate('{{log blah}}').withInput({ blah: 'whee' }).toCompileTo('');
 >       expect(calls).toEqual(callsExpected);
-631,632c536,538
+631,632c538,540
 <     it('should log at data level', function() {
 <       var called;
 ---
 >     it('should log at data level', function () {
 >       let calls = 0;
 >       const callsExpected = process.env.AST || process.env.EVAL ? 1 : 2;
-634,637c540,543
+634,637c542,545
 <       console.error = function(log) {
 <         equals('whee', log);
 <         called = true;
@@ -763,20 +766,20 @@
 >         expect('whee').toEqual(log);
 >         calls++;
 >         if (calls === callsExpected) console.error = $error;
-645c551
+645c553
 <       equals(true, called);
 ---
 >       expect(calls).toEqual(callsExpected);
-648,649c554,556
+648,649c556,558
 <     it('should handle missing logger', function() {
 <       var called = false;
 ---
 >     it('should handle missing logger', function () {
 >       let calls = 0;
 >       const callsExpected = process.env.AST || process.env.EVAL ? 1 : 2;
-650a558
+650a560
 >       // @ts-expect-error
-652,655c560,563
+652,655c562,565
 <       console.log = function(log) {
 <         equals('whee', log);
 <         called = true;
@@ -786,67 +789,67 @@
 >         expect('whee').toEqual(log);
 >         calls++;
 >         if (calls === callsExpected) console.log = $log;
-663c571
+663c573
 <       equals(true, called);
 ---
 >       expect(calls).toEqual(callsExpected);
-666,667c574,576
+666,667c576,578
 <     it('should handle string log levels', function() {
 <       var called;
 ---
 >     it('should handle string log levels', function () {
 >       let calls = 0;
 >       const callsExpected = process.env.AST || process.env.EVAL ? 1 : 2;
-669,671c578,580
+669,671c580,582
 <       console.error = function(log) {
 <         equals('whee', log);
 <         called = true;
 ---
 >       console.error = function (log) {
 >         expect('whee').toEqual(log);
 >         calls++;
-679c588
+679c590
 <       equals(true, called);
 ---
 >       expect(calls).toEqual(callsExpected);
-681c590
+681c592
 <       called = false;
 ---
 >       calls = 0;
-688c597
+688c599
 <       equals(true, called);
 ---
 >       expect(calls).toEqual(callsExpected);
-691,692c600,602
+691,692c602,604
 <     it('should handle hash log levels', function() {
 <       var called;
 ---
 >     it('should handle hash log levels [1]', function () {
 >       let calls = 0;
 >       const callsExpected = process.env.AST || process.env.EVAL ? 1 : 2;
-694,696c604,606
+694,696c606,608
 <       console.error = function(log) {
 <         equals('whee', log);
 <         called = true;
 ---
 >       console.error = function (log) {
 >         expect('whee').toEqual(log);
 >         calls++;
-699,702c609,610
+699,702c611,612
 <       expectTemplate('{{log blah level="error"}}')
 <         .withInput({ blah: 'whee' })
 <         .toCompileTo('');
 <       equals(true, called);
 ---
 >       expectTemplate('{{log blah level="error"}}').withInput({ blah: 'whee' }).toCompileTo('');
 >       expect(calls).toEqual(callsExpected);
-705,706c613,614
+705,706c615,616
 <     it('should handle hash log levels', function() {
 <       var called = false;
 ---
 >     it('should handle hash log levels [2]', function () {
 >       let called = false;
-708,711c616,623
+708,711c618,625
 <       console.info = console.log = console.error = console.debug = function() {
 <         called = true;
 <         console.info = console.log = console.error = console.debug = $log;
@@ -860,22 +863,22 @@
 >             called = true;
 >             console.info = console.log = console.error = console.debug = $log;
 >           };
-713,716c625,626
+713,716c627,628
 <       expectTemplate('{{log blah level="debug"}}')
 <         .withInput({ blah: 'whee' })
 <         .toCompileTo('');
 <       equals(false, called);
 ---
 >       expectTemplate('{{log blah level="debug"}}').withInput({ blah: 'whee' }).toCompileTo('');
 >       expect(false).toEqual(called);
-719,720c629,631
+719,720c631,633
 <     it('should pass multiple log arguments', function() {
 <       var called;
 ---
 >     it('should pass multiple log arguments', function () {
 >       let calls = 0;
 >       const callsExpected = process.env.AST || process.env.EVAL ? 1 : 2;
-722,727c633,638
+722,727c635,640
 <       console.info = console.log = function(log1, log2, log3) {
 <         equals('whee', log1);
 <         equals('foo', log2);
@@ -889,22 +892,22 @@
 >         expect(1).toEqual(log3);
 >         calls++;
 >         if (calls === callsExpected) console.log = $log;
-730,733c641,642
+730,733c643,644
 <       expectTemplate('{{log blah "foo" 1}}')
 <         .withInput({ blah: 'whee' })
 <         .toCompileTo('');
 <       equals(true, called);
 ---
 >       expectTemplate('{{log blah "foo" 1}}').withInput({ blah: 'whee' }).toCompileTo('');
 >       expect(calls).toEqual(callsExpected);
-736,737c645,647
+736,737c647,649
 <     it('should pass zero log arguments', function() {
 <       var called;
 ---
 >     it('should pass zero log arguments', function () {
 >       let calls = 0;
 >       const callsExpected = process.env.AST || process.env.EVAL ? 1 : 2;
-739,742c649,652
+739,742c651,654
 <       console.info = console.log = function() {
 <         expect(arguments.length).to.equal(0);
 <         called = true;
@@ -914,21 +917,21 @@
 >         expect(arguments.length).toEqual(0);
 >         calls++;
 >         if (calls === callsExpected) console.log = $log;
-745,748c655,656
+745,748c657,658
 <       expectTemplate('{{log}}')
 <         .withInput({ blah: 'whee' })
 <         .toCompileTo('');
 <       expect(called).to.be.true();
 ---
 >       expectTemplate('{{log}}').withInput({ blah: 'whee' }).toCompileTo('');
 >       expect(calls).toEqual(callsExpected);
-753,754c661,662
+753,754c663,664
 <   describe('#lookup', function() {
 <     it('should lookup arbitrary content', function() {
 ---
 >   describe('#lookup', () => {
 >     it('should lookup arbitrary content', () => {
-760c668
+760c670
 <     it('should not fail on undefined value', function() {
 ---
 >     it('should not fail on undefined value', () => {