From f3f0ca81a6c7479daf5fe28da847387a9ebefd4f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alejandro=20Fern=C3=A1ndez=20Haro?=
 <alejandro.haro@elastic.co>
Date: Tue, 8 Oct 2024 17:53:19 +0200
Subject: [PATCH] Add support for LiteralTemplates in `@kbn/telemetry-tools`

---
 .../__fixture__/telemetry_collectors/constants.ts     |  3 +++
 .../kbn-telemetry-tools/src/tools/serializer.test.ts  |  7 +++++++
 packages/kbn-telemetry-tools/src/tools/serializer.ts  | 11 ++++++++---
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/packages/kbn-telemetry-tools/src/tools/__fixture__/telemetry_collectors/constants.ts b/packages/kbn-telemetry-tools/src/tools/__fixture__/telemetry_collectors/constants.ts
index c9b0cbfe0281a..ec8b935912cd7 100644
--- a/packages/kbn-telemetry-tools/src/tools/__fixture__/telemetry_collectors/constants.ts
+++ b/packages/kbn-telemetry-tools/src/tools/__fixture__/telemetry_collectors/constants.ts
@@ -60,6 +60,9 @@ export interface MappedTypes {
   mappedTypeWithOneInlineProp: {
     [key in 'prop3']: number;
   };
+  mappedTypeWithLiteralTemplates: {
+    [key in MappedTypeProps | `templated_prop/${string}`]: number;
+  };
 }
 
 export type RecordWithKnownProps = Record<MappedTypeProps, number>;
diff --git a/packages/kbn-telemetry-tools/src/tools/serializer.test.ts b/packages/kbn-telemetry-tools/src/tools/serializer.test.ts
index 4301ab30fd09e..86f897767a025 100644
--- a/packages/kbn-telemetry-tools/src/tools/serializer.test.ts
+++ b/packages/kbn-telemetry-tools/src/tools/serializer.test.ts
@@ -105,6 +105,13 @@ describe('getDescriptor', () => {
       mappedTypeWithOneInlineProp: {
         prop3: { kind: ts.SyntaxKind.NumberKeyword, type: 'NumberKeyword' },
       },
+      mappedTypeWithLiteralTemplates: {
+        prop1: { kind: ts.SyntaxKind.NumberKeyword, type: 'NumberKeyword' },
+        prop2: { kind: ts.SyntaxKind.NumberKeyword, type: 'NumberKeyword' },
+        // ideally, it'd be `templated_prop/@@INDEX@@` to be more explicit. But we're going with the fuzzier approach
+        // for now as it may require more changes downstream that are not worth it.
+        '@@INDEX@@': { kind: ts.SyntaxKind.NumberKeyword, type: 'NumberKeyword' },
+      },
     });
   });
 
diff --git a/packages/kbn-telemetry-tools/src/tools/serializer.ts b/packages/kbn-telemetry-tools/src/tools/serializer.ts
index 2523bc246d2a8..0269dc446b4a0 100644
--- a/packages/kbn-telemetry-tools/src/tools/serializer.ts
+++ b/packages/kbn-telemetry-tools/src/tools/serializer.ts
@@ -99,10 +99,15 @@ export function getConstraints(node: ts.Node, program: ts.Program): any {
     return node.literal.text;
   }
 
-  if (ts.isStringLiteral(node)) {
+  if (ts.isStringLiteral(node) || ts.isStringLiteralLike(node)) {
     return node.text;
   }
 
+  // template literals such as `smth/${string}`
+  if (ts.isTemplateLiteralTypeNode(node) || ts.isTemplateExpression(node)) {
+    return '@@INDEX@@'; // just map it to any kind of string. We can enforce it further in the future if we see fit.
+  }
+
   if (ts.isImportSpecifier(node) || ts.isExportSpecifier(node)) {
     const source = node.getSourceFile();
     const importedModuleName = getModuleSpecifier(node);
@@ -180,9 +185,9 @@ export function getDescriptor(node: ts.Node, program: ts.Program): Descriptor |
       const constraintsArray = Array.isArray(constraints) ? constraints : [constraints];
       if (typeof constraintsArray[0] === 'string') {
         return constraintsArray.reduce((acc, c) => {
-          (acc as Record<string, unknown>)[c] = descriptor;
+          acc[c] = descriptor;
           return acc;
-        }, {});
+        }, {} as Record<string, unknown>);
       }
     }
     return { '@@INDEX@@': descriptor };