refactor: change template var delimiters

The current template var format `${{...}}` clashes with that used by
GitHub Actions, which makes usage unwieldy. Currently users need to
escape the `${{FILE_NAME}}` template in order to avoid it being
interpreted as a GHA template, so usage looks like:
```yaml
check_title_template: ${{ '${{FILE_NAME}}' }}
```

This commit changes the template format to `{{..}}`, so usage looks
like:
```yaml
check_title_template: '{{FILE_NAME}}'
```

This is a non-breaking change, as currently the input which makes use of
template vars isn't exposed via the action.yml file.

README.md

@@ -82,7 +82,7 @@ jobs:
 | `fail_on_failure` | Optional. Fail the build in case of a test failure.                                                                                                                |
 | `require_tests`   | Optional. Fail if no test are found..                                                                                                                              |
 | `check_retries`         | Optional. If a testcase is retried, ignore the original failure.                                                                                             |
-| `check_title_template`  | Optional. Template to configure the title format. Placeholders: ${{FILE_NAME}}, ${{SUITE_NAME}}, ${{TEST_NAME}}.                                             |
+| `check_title_template`  | Optional. Template to configure the title format. Placeholders: {{FILE_NAME}}, {{SUITE_NAME}}, {{TEST_NAME}}.                                                |
 | `summary`         | Optional. Additional text to summary output                                                                                                                        |
 | `update_check`    | Optional. Uses an alternative API to update checks, use for cases with more than 50 annotations.                                                                   |
 | `annotate_only`   | Optional. Will only annotate the results on the files, won't create a check run.                                                                                   |

__tests__/testParser.test.ts

@@ -426,7 +426,7 @@ action.surefire.report.email.InvalidEmailAddressException: Invalid email address
     });
 
     it('parse mocha test case, custom title template', async () => {
-        const { count, skipped, annotations } = await parseFile('test_results/mocha/mocha.xml', '*', true, false, ['/build/', '/__pycache__/'], '${{TEST_NAME}}');
+        const { count, skipped, annotations } = await parseFile('test_results/mocha/mocha.xml', '*', true, false, ['/build/', '/__pycache__/'], '{{TEST_NAME}}');
 
         expect(count).toBe(1);
         expect(skipped).toBe(0);

action.yml

@@ -52,7 +52,7 @@ inputs:
     default: 'false'
   check_title_template:
     description: |-
-      Template to configure the title format. Placeholders: ${{ '${{FILE_NAME}}, ${{SUITE_NAME}}, ${{TEST_NAME}}' }}.
+      Template to configure the title format. Placeholders: {{FILE_NAME}}, {{SUITE_NAME}}, {{TEST_NAME}}.
     required: false
   summary:
     description: 'Additional text to summary output'

src/testParser.ts

@@ -151,6 +151,10 @@ export async function parseFile(
   )
 }
 
+function templateVar(varName: string): string {
+  return `{{${varName}}}`
+}
+
 async function parseSuite(
   /* eslint-disable  @typescript-eslint/no-explicit-any */
   suite: any,
@@ -296,9 +300,9 @@ async function parseSuite(
           const fileName =
             pos.fileName !== testcase._attributes.name ? pos.fileName : ''
           title = checkTitleTemplate
-            .replace('${{FILE_NAME}}', fileName)
-            .replace('${{SUITE_NAME}}', suiteName ?? '')
-            .replace('${{TEST_NAME}}', testcase._attributes.name)
+            .replace(templateVar('FILE_NAME'), fileName)
+            .replace(templateVar('SUITE_NAME'), suiteName ?? '')
+            .replace(templateVar('TEST_NAME'), testcase._attributes.name)
         } else if (pos.fileName !== testcase._attributes.name) {
           title = suiteName
             ? `${pos.fileName}.${suiteName}/${testcase._attributes.name}`