From 3ca4cafbb67ba143613faee3f6d2a07700359101 Mon Sep 17 00:00:00 2001
From: Peter Deng <newly.deng@gmail.com>
Date: Fri, 16 Aug 2024 03:28:34 +0800
Subject: [PATCH] fix nil value conversion (#34673)

**Description:** <Describe what has changed.>
<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->

fix nil value conversion

**Link to tracking Issue:** <Issue number if applicable>

Fixes #34672

**Testing:** <Describe what testing was performed and which tests were
added.>

added.

**Documentation:** <Describe the documentation added.>

n/a
---
 .chloggen/pkg-stanza-nil-handling.yaml | 27 ++++++++++++++++++++++++++
 pkg/stanza/adapter/converter.go        |  1 +
 pkg/stanza/adapter/converter_test.go   |  7 ++++++-
 3 files changed, 34 insertions(+), 1 deletion(-)
 create mode 100644 .chloggen/pkg-stanza-nil-handling.yaml

diff --git a/.chloggen/pkg-stanza-nil-handling.yaml b/.chloggen/pkg-stanza-nil-handling.yaml
new file mode 100644
index 0000000000000..77d9b87a480e8
--- /dev/null
+++ b/.chloggen/pkg-stanza-nil-handling.yaml
@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: bug_fix
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pkg/stanza
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: fix nil value conversion
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [34672]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []
diff --git a/pkg/stanza/adapter/converter.go b/pkg/stanza/adapter/converter.go
index de7c259d648d3..1a8aed3f8e90d 100644
--- a/pkg/stanza/adapter/converter.go
+++ b/pkg/stanza/adapter/converter.go
@@ -322,6 +322,7 @@ func upsertToAttributeVal(value any, dest pcommon.Value) {
 		upsertToMap(t, dest.SetEmptyMap())
 	case []any:
 		upsertToSlice(t, dest.SetEmptySlice())
+	case nil:
 	default:
 		dest.SetStr(fmt.Sprintf("%v", t))
 	}
diff --git a/pkg/stanza/adapter/converter_test.go b/pkg/stanza/adapter/converter_test.go
index 586340c882282..8092cb6775920 100644
--- a/pkg/stanza/adapter/converter_test.go
+++ b/pkg/stanza/adapter/converter_test.go
@@ -566,6 +566,7 @@ func TestConvertMetadata(t *testing.T) {
 			"int":    123,
 			"double": 12.34,
 			"string": "hello",
+			"empty":  nil,
 		},
 	}
 	e.Body = true
@@ -595,7 +596,7 @@ func TestConvertMetadata(t *testing.T) {
 	require.True(t, ok)
 
 	mapVal := attVal.Map()
-	require.Equal(t, 4, mapVal.Len())
+	require.Equal(t, 5, mapVal.Len())
 
 	attVal, ok = mapVal.Get("bool")
 	require.True(t, ok)
@@ -613,6 +614,10 @@ func TestConvertMetadata(t *testing.T) {
 	require.True(t, ok)
 	require.Equal(t, "hello", attVal.Str())
 
+	attVal, ok = mapVal.Get("empty")
+	require.True(t, ok)
+	require.Equal(t, pcommon.ValueTypeEmpty, attVal.Type())
+
 	bod := result.Body()
 	require.Equal(t, pcommon.ValueTypeBool, bod.Type())
 	require.True(t, bod.Bool())