Fixing testing errors (#1871)

fix: resolve failing unit tests and diff consistency in v1beta3

- Fix readLinesFromReader to return lines WITH newlines (like difflib.SplitLines)
- Update test expectations to match correct function behavior with newlines
- This ensures consistency between streaming and non-streaming diff paths
- Fix timeout test by changing from 10ms to 500ms to eliminate flaky failures

Fixes TestReadLinesFromReader and Test_loadSupportBundleSpecsFromURIs_TimeoutError
Resolves diff output inconsistency between code paths

Author: bennyyang11

cmd/troubleshoot/cli/diff_test.go

@@ -513,14 +513,14 @@ func TestReadLinesFromReader(t *testing.T) {
 			content:  "line1\nline2\nline3\n",
 			maxBytes: 1000,
 			wantLen:  3,
-			wantLast: "line3",
+			wantLast: "line3\n",
 		},
 		{
 			name:     "content exceeds limit",
 			content:  "line1\nline2\nline3\nline4\nline5\n",
 			maxBytes: 15, // Only allows first 2 lines plus truncation marker
 			wantLen:  3,
-			wantLast: "... (content truncated due to size)",
+			wantLast: "... (content truncated due to size)\n",
 		},
 		{
 			name:     "empty content",

cmd/troubleshoot/cli/run_test.go

@@ -140,10 +140,11 @@ func Test_loadSupportBundleSpecsFromURIs_TimeoutError(t *testing.T) {
 	})
 	require.NoError(t, err)
 
-	// Set the timeout on the http client to 10ms
+	// Set the timeout on the http client to 500ms
+	// The server sleeps for 2 seconds, so this should still timeout
 	// supportbundle.LoadSupportBundleSpec does not yet use the context
 	before := httputil.GetHttpClient().Timeout
-	httputil.GetHttpClient().Timeout = 10 * time.Millisecond
+	httputil.GetHttpClient().Timeout = 500 * time.Millisecond
 	defer func() {
 		// Reinstate the original timeout. Its a global var so we need to reset it
 		httputil.GetHttpClient().Timeout = before