SCR124: trailing-whitespace

Spaces or tabs at the end of a script line

Code	SCR124
Name	trailing-whitespace
Category	Scripts (SCR)
Default severity	info
Enabled by default	no
Fix available	always
Fix safety	safe or unsafe, depending on the finding (see below)
ign-lint equivalent	none

What it does

Reports spaces, tabs and form feeds at the end of script lines, also on lines that hold nothing else, in library modules, event files and every script embedded in a view or another resource.

Whitespace inside a multi-line string literal is part of the string's value and is not reported, and so is whitespace after a backslash in a single-quoted string that a line break ends: Jython drops such a string with the line break and lexes on, and without the whitespace the backslash would continue the string on the next line. Scripts that do not parse are not checked (SCR001 reports them).

Why is this bad?

Trailing whitespace is invisible in the Designer's script editor, makes diffs noisy and often differs between developers' editors, so the same script keeps changing in version control.

Example

def runAction(self, event):
  value = event.value
  self.props.text = value

Use instead:

def runAction(self, event):
  value = event.value
  self.props.text = value

Fix

Removes the whitespace. Safe: the whitespace is in no value and no line moves. The fix only changes layout, so it is safe only when every token of the script stays as it is (checked by lexing the script before and after); whitespace that Jython's lexer reads, such as the whitespace after a backslash that is not followed by a line break, makes it unsafe. Like every fix, it is unsafe while code in the workspace may read the files a fix edits (any file access, read, write, rename or delete, whose path is not a literal outside the workspace, or code that is not vetted); the project setting [fix] assume-scripts-do-not-read-workspace-files = true declares that no script does (see docs/internal/fix-safety.md, "File reads").

pylint

Corresponds to C0303 trailing-whitespace.

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Generated from the rule metadata by iglint generate-docs; iglint rule SCR124 prints the same page in the terminal. Source: docs/rules/SCR124.md.