Roslynator analyzer warnings

Use this skill when the build reports an RCS* diagnostic from Roslynator analyzers.

Roslynator analyzers (RCS)

RCS0003 - Add blank line after using directive list

What it flags: Roslynator reports code that violates this rule: Add blank line after using directive list.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0003

Example:

• Bad: using System; is followed immediately by namespace App;.
• Fix: add a blank line between the using list and the namespace/type.

RCS0041 - Remove new line between 'if' keyword and 'else' keyword

What it flags: Roslynator reports code that violates this rule: Remove new line between 'if' keyword and 'else' keyword.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0041

Example:

• Bad: } and else are separated by an extra newline.
• Fix: keep else directly after the closing brace according to project style.

RCS0044 - Use carriage return + linefeed as new line

What it flags: Roslynator reports code that violates this rule: Use carriage return + linefeed as new line.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0044

Example:

• Bad: file uses LF-only line endings.
• Fix: save the file with CRLF line endings.

RCS0046 - Use spaces instead of tab

What it flags: Roslynator reports code that violates this rule: Use spaces instead of tab.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0046

Example:

• Bad: indentation contains tab characters.
• Fix: replace tabs with spaces.

RCS0058 - Normalize whitespace at the end of a file

What it flags: Roslynator reports code that violates this rule: Normalize whitespace at the end of a file.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0058

Example:

• Bad: trailing spaces or extra whitespace at the end of a file.
• Fix: remove end-of-file whitespace and keep one final newline.

RCS0063 - Remove unnecessary blank line

What it flags: Roslynator reports code that violates this rule: Remove unnecessary blank line.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0063

Example:

• Bad: an extra blank line splits code where the style expects none.
• Fix: remove the unnecessary blank line.

RCS1001 - Add braces (when expression spans over multiple lines)

What it flags: Roslynator reports code that violates this rule: Add braces (when expression spans over multiple lines).

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1001

Example:

• Bad: a multiline if body is written without braces.
• Fix: add braces when the expression spans multiple lines.

RCS1003 - Add braces to if-else (when expression spans over multiple lines)

What it flags: Roslynator reports code that violates this rule: Add braces to if-else (when expression spans over multiple lines).

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1003

Example:

• Bad: multiline if/else branches omit braces.
• Fix: add braces to both branches.

RCS1013 - Use predefined type

What it flags: Roslynator reports code that violates this rule: Use predefined type.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1013

Example:

• Bad: System.String value in C# code.
• Fix: use predefined aliases such as string, int, and bool.

RCS1016 - Use block body or expression body

What it flags: Roslynator reports code that violates this rule: Use block body or expression body.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1016

Example:

• Bad: member body form differs from configured style.
• Fix: convert between block body and expression body as requested.

RCS1019 - Order modifiers

What it flags: Roslynator reports code that violates this rule: Order modifiers.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1019

Example:

• Bad: static public.
• Fix: use standard order, e.g. public static.

RCS1034 - Remove redundant 'sealed' modifier

What it flags: Roslynator reports code that violates this rule: Remove redundant 'sealed' modifier.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1034

Example:

• Bad: redundant sealed modifier is present.
• Fix: remove sealed where Roslynator reports it redundant.

RCS1035 - Remove redundant comma in initializer

What it flags: Roslynator reports code that violates this rule: Remove redundant comma in initializer.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1035

Example:

• Bad: new[] { 1, 2, } where style disallows the comma.
• Fix: remove the redundant comma.

RCS1037 - Remove trailing white-space

What it flags: Roslynator reports code that violates this rule: Remove trailing white-space.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1037

Example:

• Bad: a line ends with spaces before the newline.
• Fix: remove trailing whitespace.

RCS1038 - Remove empty statement

What it flags: Roslynator reports code that violates this rule: Remove empty statement.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1038

Example:

• Bad: a stray ; creates an empty statement.
• Fix: remove the empty statement.

RCS1039 - Remove argument list from attribute

What it flags: Roslynator reports code that violates this rule: Remove argument list from attribute.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1039

Example:

• Bad: [Obsolete()] when no arguments are supplied.
• Fix: use [Obsolete].

RCS1044 - Remove original exception from throw statement

What it flags: Roslynator reports code that violates this rule: Remove original exception from throw statement.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1044

Example:

• Bad: catch (Exception ex) { throw ex; }.
• Fix: use throw; to preserve the stack trace.

RCS1047 - Non-asynchronous method name should not end with 'Async'

What it flags: Roslynator reports code that violates this rule: Non-asynchronous method name should not end with 'Async'.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1047

Example:

• Bad: public void SaveAsync() returns void.
• Fix: return Task or rename the method.

RCS1055 - Unnecessary semicolon at the end of declaration

What it flags: Roslynator reports code that violates this rule: Unnecessary semicolon at the end of declaration.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1055

Example:

• Bad: public string Name { get; set; };.
• Fix: remove the unnecessary semicolon.

RCS1059 - Avoid locking on publicly accessible instance

What it flags: Roslynator reports code that violates this rule: Avoid locking on publicly accessible instance.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1059

Example:

• Bad: lock (this) or lock (typeof(Foo)).
• Fix: lock on a private readonly object.

RCS1060 - Declare each type in separate file

What it flags: Roslynator reports code that violates this rule: Declare each type in separate file.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1060

Example:

• Bad: one file declares unrelated top-level types.
• Fix: move each top-level type to its own file.

RCS1075 - Avoid empty catch clause that catches System. Exception

What it flags: Roslynator reports code that violates this rule: Avoid empty catch clause that catches System. Exception.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1075

Example:

• Bad: catch (Exception) { }.
• Fix: handle, log, rethrow, or remove the catch.

RCS1091 - Remove empty region

What it flags: Roslynator reports code that violates this rule: Remove empty region.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1091

Example:

• Bad: #region Old code contains no members.
• Fix: remove the empty region.

RCS1093 - File contains no code

What it flags: Roslynator reports code that violates this rule: File contains no code.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1093

Example:

• Bad: a .cs file contains only comments or whitespace.
• Fix: remove the file or add the intended code.

RCS1094 - Declare using directive on top level

What it flags: Roslynator reports code that violates this rule: Declare using directive on top level.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1094

Example:

• Bad: using System; is inside a namespace when top-level usings are expected.
• Fix: move using directives to the top level.

RCS1102 - Make class static

What it flags: Roslynator reports code that violates this rule: Make class static.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1102

Example:

• Bad: a class contains only static members but is not static.
• Fix: mark the class static.

RCS1110 - Declare type inside namespace

What it flags: Roslynator reports code that violates this rule: Declare type inside namespace.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1110

Example:

• Bad: top-level type is declared outside a namespace.
• Fix: put the type in the correct namespace.

RCS1145 - Remove redundant 'as' operator

What it flags: Roslynator reports code that violates this rule: Remove redundant 'as' operator.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1145

Example:

• Bad: var text = value as string; where value is already string.
• Fix: remove the redundant as conversion.

RCS1172 - Use 'is' operator instead of 'as' operator

What it flags: Roslynator reports code that violates this rule: Use 'is' operator instead of 'as' operator.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1172

Example:

• Bad: var c = o as Control; if (c != null) ....
• Fix: use if (o is Control c) ....

RCS1211 - Remove unnecessary 'else'

What it flags: Roslynator reports code that violates this rule: Remove unnecessary 'else'.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1211

Example:

• Bad: if (done) { return; } else { Work(); }.
• Fix: remove the unnecessary else.

RCS1225 - Make class sealed

What it flags: Roslynator reports code that violates this rule: Make class sealed.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1225

Example:

• Bad: class can be inherited although no inheritance is intended.
• Fix: mark the class sealed when appropriate.

RCS1242 - Do not pass non-read-only struct by read-only reference

What it flags: Roslynator reports code that violates this rule: Do not pass non-read-only struct by read-only reference.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1242

Example:

• Bad: void M(in MutableStruct value) for a non-readonly struct.
• Fix: pass by value or make the struct readonly if intended.

RCS1259 - Remove empty syntax

What it flags: Roslynator reports code that violates this rule: Remove empty syntax.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1259

Example:

• Bad: empty braces, argument list, or similar empty syntax remains.
• Fix: remove the empty syntax.

RCS1260 - Add/remove trailing comma

What it flags: Roslynator reports code that violates this rule: Add/remove trailing comma.

Documentation: https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1260

Example:

• Bad: initializer comma style differs from formatter settings.
• Fix: add or remove the trailing comma to match the rule.