[ResponseOps] mustache lambdas for EncodeURI and EncodeURIComponent, take 2 (elastic#213859)

resolves elastic#168728

## Release note

Adds Mustache lambdas for alerting actions to encode URLs with
`{{#EncodeURI}}` and `{{#EncodeURIComponent}}` using `encodeURI()` and
`encodeURIComponent()`.

doc to update, in a separate PR:
elastic/docs-content#735

(cherry picked from commit a3aaa04)

Author: pmuellr

x-pack/platform/plugins/shared/actions/server/lib/mustache_lambdas.test.ts

@@ -246,4 +246,52 @@ describe('mustache lambdas', () => {
       expect(logger.warn).toHaveBeenCalledWith(`mustache render error: invalid number: 'nope'`);
     });
   });
+
+  describe('EncodeURI', () => {
+    it('valid string is successful', () => {
+      const uri = 'https://www.elastic.co?foo=bar&baz= qux'; // note the space
+      const template = dedent`
+          {{#EncodeURI}}{{uri}}{{/EncodeURI}}
+        `.trim();
+
+      expect(renderMustacheString(logger, template, { uri }, 'none')).toEqual(
+        'https://www.elastic.co?foo=bar&baz=%20qux'
+      );
+    });
+
+    it('logs an error message and returns the error message on errors', () => {
+      const uri = '\uDC00'; // invalid UTF-8
+      const template = dedent`
+          {{#EncodeURI}} {{uri}} {{/EncodeURI}}
+        `.trim();
+
+      const errMessage = `error evaluating encodeURI(\" ${uri} \"): URI malformed`;
+      expect(renderMustacheString(logger, template, { uri }, 'none')).toBe(errMessage);
+      expect(logger.warn).toHaveBeenCalledWith(`mustache render error: ${errMessage}`);
+    });
+  });
+
+  describe('EncodeURIComponent', () => {
+    it('valid string is successful', () => {
+      const uri = 'https://www.elastic.co?foo=bar&baz= qux'; // note the space
+      const template = dedent`
+          {{#EncodeURIComponent}}{{uri}} {{/EncodeURIComponent}}
+        `.trim();
+
+      expect(renderMustacheString(logger, template, { uri }, 'none')).toEqual(
+        'https%3A%2F%2Fwww.elastic.co%3Ffoo%3Dbar%26baz%3D%20qux%20'
+      );
+    });
+
+    it('logs an error message and returns the error message on errors', () => {
+      const uri = '\uDC00'; // invalid UTF-8
+      const template = dedent`
+          {{#EncodeURIComponent}} {{uri}} {{/EncodeURIComponent}}
+        `.trim();
+
+      const errMessage = `error evaluating encodeURIComponent(\" ${uri} \"): URI malformed`;
+      expect(renderMustacheString(logger, template, { uri }, 'none')).toBe(errMessage);
+      expect(logger.warn).toHaveBeenCalledWith(`mustache render error: ${errMessage}`);
+    });
+  });
 });

x-pack/platform/plugins/shared/actions/server/lib/mustache_lambdas.ts

@@ -46,9 +46,39 @@ function getLambdas(logger: Logger) {
         const numberString = render(text.trim()).trim();
         return formatNumber(logger, numberString);
       },
+    EncodeURI: () =>
+      function (text: string, render: RenderFn) {
+        // specifically does not strip whitespace
+        const string = render(text);
+        return callEncodeURI(logger, string);
+      },
+    EncodeURIComponent: () =>
+      function (text: string, render: RenderFn) {
+        // specifically does not strip whitespace
+        const string = render(text);
+        return callEncodeURIComponent(logger, string);
+      },
   };
 }
 
+function callEncodeURI(logger: Logger, string: string): string {
+  const s = `${string}`;
+  try {
+    return encodeURI(s);
+  } catch (err) {
+    return logAndReturnErr(logger, `error evaluating encodeURI("${s}"): ${err.message}`);
+  }
+}
+
+function callEncodeURIComponent(logger: Logger, string: string): string {
+  const s = `${string}`;
+  try {
+    return encodeURIComponent(s);
+  } catch (err) {
+    return logAndReturnErr(logger, `error evaluating encodeURIComponent("${s}"): ${err.message}`);
+  }
+}
+
 function evalMath(vars: Variables, o: unknown, logger: Logger): string {
   const expr = `${o}`;
   try {

x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts

@@ -48,6 +48,7 @@ export const DeepContextVariables = {
   nullJ: null,
   undefinedK: undefined,
   dateL: '2023-04-20T04:13:17.858Z',
+  encodeableUrl: 'https://www.elastic.co?foo=bar&baz= qux',
 };
 
 function getAlwaysFiringRuleType() {

x-pack/test/alerting_api_integration/spaces_only/tests/alerting/group4/mustache_templates.ts

@@ -66,7 +66,7 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
 
     describe('escaping', () => {
       it('should handle escapes in webhook', async () => {
-        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/alert_types.ts,
+        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
         // const EscapableStrings
         const template = '{{context.escapableDoubleQuote}} -- {{context.escapableLineFeed}}';
         const rule = await createRule({
@@ -81,7 +81,7 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
       });
 
       it('should handle escapes in slack', async () => {
-        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/alert_types.ts,
+        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
         // const EscapableStrings
         const template =
           '{{context.escapableBacktic}} -- {{context.escapableBold}} -- {{context.escapableBackticBold}} -- {{context.escapableHtml}} -- {{context.escapableLink}}';
@@ -101,7 +101,7 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
       });
 
       it('should handle context variable object expansion', async () => {
-        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/alert_types.ts,
+        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
         // const DeepContextVariables
         const template = '{{context.deep}}';
         const rule = await createRule({
@@ -113,7 +113,7 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
         });
         const body = await retry.try(async () => waitForActionBody(slackSimulatorURL, rule.id));
         expect(body).to.be(
-          '{"objectA":{"stringB":"B","arrayC":[{"stringD":"D1","numberE":42},{"stringD":"D2","numberE":43}],"objectF":{"stringG":"G","nullG":null}},"stringH":"H","arrayI":[44,45],"nullJ":null,"dateL":"2023-04-20T04:13:17.858Z"}'
+          '{"objectA":{"stringB":"B","arrayC":[{"stringD":"D1","numberE":42},{"stringD":"D2","numberE":43}],"objectF":{"stringG":"G","nullG":null}},"stringH":"H","arrayI":[44,45],"nullJ":null,"dateL":"2023-04-20T04:13:17.858Z","encodeableUrl":"https://www.elastic.co?foo=bar&baz= qux"}'
         );
       });
 
@@ -165,7 +165,7 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
       });
 
       it('should handle asJSON', async () => {
-        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/alert_types.ts,
+        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
         // const DeepContextVariables
         const template = `{{#context.deep.objectA}}
           {{{arrayC}}} {{{arrayC.asJSON}}}
@@ -185,7 +185,7 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
       });
 
       it('should handle EvalMath', async () => {
-        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/alert_types.ts,
+        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
         // const DeepContextVariables
         const template = `{{#context.deep}}avg({{arrayI.0}}, {{arrayI.1}})/100 => {{#EvalMath}}
           round((arrayI[0] + arrayI[1]) / 2 / 100, 2)
@@ -202,7 +202,7 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
       });
 
       it('should handle FormatDate', async () => {
-        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/alert_types.ts,
+        // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
         // const DeepContextVariables
         const template = `{{#context.deep}}{{#FormatDate}}
           {{{dateL}}} ; America/New_York; dddd MMM Do YYYY HH:mm:ss
@@ -220,7 +220,7 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
     });
 
     it('should handle FormatNumber', async () => {
-      // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/alert_types.ts,
+      // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
       // const DeepContextVariables
       const template = `{{#context.deep}}{{#FormatNumber}}
         {{{arrayI.1}}}; en-US; style: currency, currency: EUR
@@ -236,6 +236,36 @@ export default function executionStatusAlertTests({ getService }: FtrProviderCon
       expect(body.trim()).to.be('€45.00');
     });
 
+    it('should handle EncodeURI', async () => {
+      // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
+      // const DeepContextVariables
+      const template = `{{#context.deep}}{{#EncodeURI}}{{{encodeableUrl}}}{{/EncodeURI}}{{/context.deep}}`;
+      const rule = await createRule({
+        id: slackConnector.id,
+        group: 'default',
+        params: {
+          message: `message {{rule.id}} - ${template}`,
+        },
+      });
+      const body = await retry.try(async () => waitForActionBody(slackSimulatorURL, rule.id));
+      expect(body.trim()).to.be('https://www.elastic.co?foo=bar&baz=%20qux');
+    });
+
+    it('should handle EncodeURIComponent', async () => {
+      // from x-pack/test/alerting_api_integration/common/plugins/alerts/server/rule_types.ts
+      // const DeepContextVariables
+      const template = `{{#context.deep}}{{#EncodeURIComponent}}{{{encodeableUrl}}}{{/EncodeURIComponent}}{{/context.deep}}`;
+      const rule = await createRule({
+        id: slackConnector.id,
+        group: 'default',
+        params: {
+          message: `message {{rule.id}} - ${template}`,
+        },
+      });
+      const body = await retry.try(async () => waitForActionBody(slackSimulatorURL, rule.id));
+      expect(body.trim()).to.be('https%3A%2F%2Fwww.elastic.co%3Ffoo%3Dbar%26baz%3D%20qux');
+    });
+
     async function createRule(action: any) {
       const ruleResponse = await supertest
         .post(`${getUrlPrefix(Spaces.space1.id)}/api/alerting/rule`)