From 9eb47e4eeff895761459f8f4ffbd5f0050ede049 Mon Sep 17 00:00:00 2001
From: Ignacio Rivas <rivasign@gmail.com>
Date: Tue, 22 Jul 2025 09:18:24 +0300
Subject: [PATCH] [Ingest Pipelines] Fix empty string bug (#228717)

(cherry picked from commit 462e7bd41ab3b23f4cc4a892b07a98255cbd85fa)
---
 .../components/pipeline_editor/utils.test.ts  | 49 +++++++++++++++++++
 .../components/pipeline_editor/utils.ts       |  7 ++-
 2 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/x-pack/plugins/ingest_pipelines/public/application/components/pipeline_editor/utils.test.ts b/x-pack/plugins/ingest_pipelines/public/application/components/pipeline_editor/utils.test.ts
index bda9468cc718a..cedcfe1ee3cc1 100644
--- a/x-pack/plugins/ingest_pipelines/public/application/components/pipeline_editor/utils.test.ts
+++ b/x-pack/plugins/ingest_pipelines/public/application/components/pipeline_editor/utils.test.ts
@@ -70,4 +70,53 @@ describe('convert processors to json', () => {
       customProcessor: 'aaa"bbb',
     });
   });
+
+  it('preserves empty string values', () => {
+    const obj = {
+      field1: 'normalString',
+      value: '',
+      inference_config: '',
+      field_map: '',
+      params: '',
+      pattern_definitions: '',
+      processor: '',
+      customOptions: '',
+    };
+
+    const result = convertProccesorsToJson(obj);
+
+    expect(result).toEqual({
+      field1: 'normalString',
+      value: '',
+      inference_config: '',
+      field_map: '',
+      params: '',
+      pattern_definitions: '',
+      processor: '',
+    });
+
+    // Explicitly check that empty strings are preserved and not converted to undefined
+    expect(result.value).toBe('');
+    expect(result.inference_config).toBe('');
+    expect(result.field_map).toBe('');
+    expect(result.params).toBe('');
+    expect(result.pattern_definitions).toBe('');
+    expect(result.processor).toBe('');
+  });
+
+  it('handles null and undefined values correctly', () => {
+    const obj = {
+      value: null,
+      inference_config: undefined,
+      field_map: 'normalString',
+    };
+
+    const result = convertProccesorsToJson(obj);
+
+    expect(result).toEqual({
+      value: undefined,
+      inference_config: undefined,
+      field_map: 'normalString',
+    });
+  });
 });
diff --git a/x-pack/plugins/ingest_pipelines/public/application/components/pipeline_editor/utils.ts b/x-pack/plugins/ingest_pipelines/public/application/components/pipeline_editor/utils.ts
index 81149830eb62b..eb0458070bc53 100644
--- a/x-pack/plugins/ingest_pipelines/public/application/components/pipeline_editor/utils.ts
+++ b/x-pack/plugins/ingest_pipelines/public/application/components/pipeline_editor/utils.ts
@@ -129,10 +129,15 @@ const escapeLiteralStrings = (data: string): string[] => {
 };
 
 const convertProcessorValueToJson = (data: string): any => {
-  if (!data) {
+  if (data === null || data === undefined) {
     return undefined;
   }
 
+  // Preserve empty strings
+  if (data === '') {
+    return data;
+  }
+
   try {
     const escapedData = escapeLiteralStrings(data);
     return JSON.parse(escapedData.join(''));