A Prettier plugin for preserving lines.

    Preserve first blank line of a block:     An expression:

        if (condition) {                          matrix = [  //
                                                      1, 0, 1,
          statement1;                                 0, 1, 0,
          statement2;                                 0, 0, 1,
                                                  ];
          statement3;
          statement4;
        }

    Preserve method chain breaks:

        cy.get("something")
          .style().isBold()
          .value().matches('abc')
          .hasAttribute({
              name: "explanation",
              xyz: true
          })
          .done();

.

For Prettier v2:

npm install -D prettier@^2 @yikes2000/prettier-plugin-preserve-line

For Prettier v3:[^1]

npm install -D prettier @yikes2000/prettier-plugin-preserve-line

.

JSON example:

{
  "plugins": ["@yikes2000/prettier-plugin-preserve-line"]
}

JS example (CommonJS module):

module.exports = {
  plugins: ['@yikes2000/prettier-plugin-preserve-line'],
  preserveFirstBlankLine: true,
  preserveEolMarker: true,
};

JS example (ES module):

export default {
  plugins: ['@yikes2000/prettier-plugin-preserve-line'],
  preserveFirstBlankLine: true,
  preserveEolMarker: true,
};

.

Preserve the first blank line of a block (curly, bracket, or parenthesis).

Example:

  if (condition) {

    statement1;
    statement2;

    statement3;
    statement4;
  }

  a = [

    // Odds
    1, 3, 5, 7, 9,

    // Evens
    2, 4, 6, 8, 10,
  ];

  sum = (

    // Odds
    1 + 3 + 5 + 7 + 9 +

    // Evens
    2 + 4 + 6 + 8 + 10
  );

Preserve the last blank line of a block (curly, bracket, or parenthesis).

Example:

  if (condition) {
    statement1;
    statement2;

  }

  a = [
    // Odds
    1, 3, 5, 7, 9,

    // Evens
    2, 4, 6, 8, 10,

  ];

  sum = (
    // Odds
    1 + 3 + 5 + 7 + 9 +

    // Evens
    2 + 4 + 6 + 8 + 10

  );

.

End-of-line "//" marker applies "// prettier-ignore" to that line.

Example:

  matrix = [  //
    1, 0, 1,
    0, 1, 0,
    0, 0, 1,
  ];

  msg =  //
      matrix.length < 9 ? 'too smalt'
    : matrix.length > 9 ? 'too big'
    :                     'just right';

.

Prettier formats method chain in one of two styles:

  cy.all().in().one().line();

  cy.tooManyForOneLine()
    .split()
    .them()
    .into()
    .multiple()
    .lines();

This option preserves existing method chain breaks:

  cy.get("something")
    .value().matches('abc').matches('cde')
    .allowing({
        name: "explanation",
        xyz: true
    }).andMore()
    .done();

(Indentation is still handled by Prettier.)

For local exceptions, prepend "// no-preserve" line:

  // no-preserve
  cy.get("something").old().style();

  // no-preserve
  cy.get("something")
    .tooManyForOneLine()
    .one()
    .two()
    .three();

Prettier will format the line block after "// no-preserve".

.

See @yikes2000/prettier-plugin-merge-preserve. .

Seeking contributors to support additional languages.

These preserve-line options are implemented using RegExp, which is the simplest but hacky way to achieve these results considering the rigid complexity of Prettier's internal parser and AST format. In a few rare situations these preserve options won't work, due to the limit of this RegExp approach. Please kindly report them regardless.

This plugin was templated from Hyeonjong's prettier-plugin-brace-style.