name: dart-multiline-strings\ndescription: |-\nGuidelines and best practices for refactoring consecutive prints, single-line\nstring concatenations, and complex output blocks into triple-quoted multi-line\nstring literals (''' or \"\"\") in Dart.\nlicense: Apache-2.0\nkey_features:
\nUse this skill when:
\nprint() or stdout.writeln() statements into a\nsingle, cohesive output block.\\n), or use nested indentations.Do NOT refactor to multiline strings when:
\nintl, ARB files), where line breaks or formatting must conform\nto external translation tooling.To find candidate code blocks for multi-line string refactoring:
\nprint() or stdout.writeln() calls inside a\nfunction, especially inside loops, console views, or CLI controllers.\\n escape sequences.+ operator or adjacent\nstring literal splits that are meant to represent multi-line outputs.Instead of calling print() repeatedly for a multi-line output, group the\ncontents into a single triple-quoted string literal: print('''...''').
In a triple-quoted literal, the exact spacing and formatting inside the quotes\nare preserved. Use this to specify indentation levels visually instead of using\nmanually padded space prefixes (e.g., ' ').
If there are empty print() or print('') statements serving as vertical\nseparators between output segments, replace them by letting the trailing newline\nof a multi-line string block handle the separation naturally.
If the opening triple-quote is immediately followed by a newline, the compiler\ndiscards it.
\n\\n explicitly at the beginning:\nprint('''\n\nThis starts with one blank line above it.''');\nprint()print() automatically appends a trailing newline to the printed output.
''' on a new line (\\n''');), an extra trailing\nblank line will be printed.// ✅ Emits standard output with no extra trailing empty line:\nprint('''\nHeader\nContent''');\nWhen injecting optional content via interpolation (${condition ? '...' : ''}),\nplacing the ${...} on its own line leaves behind its enclosing newline when\nthe condition evaluates to '', producing an empty blank line in the output.
// ✅ Clean conditional rendering without ghost blank lines:\nprint('''\nBranch Details:\n Name: $branch${hasWarning ? '\\n WARNING: $warningMessage' : ''}''');\nThe lines_longer_than_80_chars lint rule automatically ignores lines\ninside multiline string literals. You can write long lines inside triple-quotes\nwithout triggering linter warnings or being forced to break them up.
Leverage Dart 3 switch expressions directly inside string interpolations to\ndynamically select and inject optional lines, conditional labels, or helper\ninstructions. This avoids cluttering the surrounding code with imperatively\nconstructed strings or multiple if statements:
print('''\nStatus: ${status.isSuccess ? 'PASS' : 'FAIL'}${switch (status) {\n Status.failed => '\\nError details: $errorMessage',\n _ => '',\n}}''');\nAvoid:
\nvoid printGerritView(String branch, String desc, bool hasConflicts) {\n print('Branch Details:');\n print(' Name: ' + branch);\n print(' Description: ' + desc);\n print('');\n if (hasConflicts) {\n print(' WARNING: This branch has conflicts.');\n print(' Run `git merge origin/main` to resolve.');\n }\n}\nPrefer:
\nvoid printGerritView(String branch, String desc, bool hasConflicts) {\n print('''\nBranch Details:\n Name: $branch\n Description: $desc${hasConflicts ? '''\n\n WARNING: This branch has conflicts.\n Run `git merge origin/main` to resolve.''' : ''}''');\n}\n