Apply suggestion from @Copilot

eiriktsarpalis · Copilot · web-flow · commit ed3bcc332336 · 2025-10-08T22:15:17.000+03:00
Co-authored-by: Copilot &lt;175728472+Copilot@users.noreply.github.com&gt;
diff --git a/src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Unit.Tests/CompilationHelper.cs b/src/libraries/System.Text.Json/tests/System.Text.Json.SourceGeneration.Unit.Tests/CompilationHelper.cs
@@ -889,11 +889,11 @@ public override void Write(string? value)
 
                 if (value.EndsWith("\r\n", StringComparison.Ordinal))
                 {
-                    WriteLine(value.Substring(0, value.Length - 2));
+                    WriteLine(value[..^2]);
                 }
                 else if (value.EndsWith("\n", StringComparison.Ordinal))
                 {
-                    WriteLine(value.Substring(0, value.Length - 1));
+                    WriteLine(value[..^1]);
                 }
                 else
                 {

Original file line number	Diff line number	Diff line change
`@@ -889,11 +889,11 @@ public override void Write(string? value)`
`889`	`889`
`890`	`890`	`if (value.EndsWith("\r\n", StringComparison.Ordinal))`
`891`	`891`	`{`
`892`		`- WriteLine(value.Substring(0, value.Length - 2));`
	`892`	`+ WriteLine(value[..^2]);`
`893`	`893`	`}`
`894`	`894`	`else if (value.EndsWith("\n", StringComparison.Ordinal))`
`895`	`895`	`{`
`896`		`- WriteLine(value.Substring(0, value.Length - 1));`
	`896`	`+ WriteLine(value[..^1]);`
`897`	`897`	`}`
`898`	`898`	`else`
`899`	`899`	`{`