Change range formatting approach

NOTE: This doesn't pass its test yet. Note that since we're reading the indentation from the first line, it is expected not to change. However, a semicolon is added, and the lines outside the range are not changed. The new approach is roughly: * Require that the range exactly covers an integer number of lines of the input * Detect the indentation of the line the range starts on * Format the range's substring using `printAstToDoc` * Add enough `indent`s to the doc to restore the detected indentation * Format the doc to a string with `printDocToString` * Prepend/append the original input before/after the range See #1609 (comment) --- Given `tests/range/range.js`, run the following: prettier tests/range/range.js --range-start 165 --range-end 246 See the range's text with: dd if=tests/range/range.js ibs=1 skip=165 count=81 2>/dev/null
prettier · vjeux · May 21, 2017 · May 14, 2017 · May 14, 2017 · May 15, 2017
commit 44bfd9b0d72911f177075a2108153a8681ab1cb4
diff --git a/README.md b/README.md
@@ -254,8 +254,8 @@ Prettier ships with a handful of customizable format options, usable in both the
 | **JSX Brackets on Same Line** - Put the `>` of a multi-line JSX element at the end of the last line instead of being alone on the next line | `false` | `--jsx-bracket-same-line` | `jsxBracketSameLine: <bool>` |
 | **Parser** - Specify which parser to use. | `babylon` | <code>--parser <flow&#124;babylon></code> | <code>parser: "<flow&#124;babylon>"</code> |
 | **Semicolons** - Print semicolons at the ends of statements.<br /><br />Valid options: <br /> - `true` - add a semicolon at the end of every statement <br /> - `false` - only add semicolons at the beginning of lines that may introduce ASI failures | `true` | `--no-semi` | `semi: <bool>` |
-| **Range Start** - Format code starting at a given character offset. | `0` | `--range-start <int>` | `rangeStart: <int>` |
-| **Range End** - Format code ending at a given character offset (exclusive). | `Infinity` | `--range-end <int>` | `rangeEnd: <int>` |
+| **Range Start** - Format code starting at a given character offset. The range must begin immediately before the start of a line. | `0` | `--range-start <int>` | `rangeStart: <int>` |
+| **Range End** - Format code ending at a given character offset (exclusive). The range must end immediately after the end of a line. | `Infinity` | `--range-end <int>` | `rangeEnd: <int>` |
 
 ### Excluding code from formatting
 

diff --git a/bin/prettier.js b/bin/prettier.js
@@ -219,8 +219,8 @@ if (argv["help"] || (!filepatterns.length && !stdin)) {
       "  --trailing-comma <none|es5|all>\n" +
       "                           Print trailing commas wherever possible. Defaults to none.\n" +
       "  --parser <flow|babylon>  Specify which parse to use. Defaults to babylon.\n" +
-      "  --range-start <int>      Format code starting at a given character offset. Defaults to 0.\n" +
-      "  --range-end <int>        Format code ending at a given character offset (exclusive). Defaults to Infinity.\n" +
+      "  --range-start <int>      Format code starting at a given character offset. Must be at the start of a line. Defaults to 0.\n" +
+      "  --range-end <int>        Format code ending at a given character offset (exclusive). Must be at the end of a line. Defaults to Infinity.\n" +
       "  --no-color               Do not colorize error messages.\n" +
       "  --version or -v          Print Prettier version.\n" +
       "\n"

diff --git a/index.js b/index.js
@@ -1,7 +1,6 @@
 "use strict";
 
 const comments = require("./src/comments");
-const util = require('./src/util');
 const version = require("./package.json").version;
 const printAstToDoc = require("./src/printer").printAstToDoc;
 const printDocToString = require("./src/doc-printer").printDocToString;
@@ -28,7 +27,7 @@ function attachComments(text, ast, opts) {
   return astComments;
 }
 
-function ensureAllCommentsPrinted(astComments, opts) {
+function ensureAllCommentsPrinted(astComments) {
   for (let i = 0; i < astComments.length; ++i) {
     if (astComments[i].value.trim() === "prettier-ignore") {
       // If there's a prettier-ignore, we're not printing that sub-tree so we
@@ -38,10 +37,7 @@ function ensureAllCommentsPrinted(astComments, opts) {
   }
 
   astComments.forEach(comment => {
-    if (
-      !comment.printed &&
-      !util.isOutsideRange(comment, opts.rangeStart, opts.rangeEnd)
-    ) {
+    if (!comment.printed) {
       throw new Error(
         'Comment "' +
           comment.value.trim() +
@@ -52,16 +48,43 @@ function ensureAllCommentsPrinted(astComments, opts) {
   });
 }
 
-function format(text, opts) {
+function format(text, opts, addIndents = 0) {
+  const rangeStart = opts.rangeStart;
+  const rangeEnd = Math.min(opts.rangeEnd, text.length)
+
+  if (0 < rangeStart || rangeEnd < text.length) {
+    const rangeString = text.substring(rangeStart, rangeEnd)
+    const numIndents = countIndents(rangeString, opts);
+
+    const rangeFormatted = format(rangeString, Object.assign({}, opts, {
+      rangeStart: 0,
+      rangeEnd: Infinity,
+      printWidth: opts.printWidth - numIndents * opts.tabWidth
+    }), numIndents);
+
+    return text.slice(0, rangeStart) + rangeFormatted + text.slice(rangeEnd)
+  }
+
   const ast = parser.parse(text, opts);
   const astComments = attachComments(text, ast, opts);
-  const doc = printAstToDoc(ast, opts);
+  const doc = printAstToDoc(ast, opts, addIndents)
   opts.newLine = guessLineEnding(text);
   const str = printDocToString(doc, opts);
-  ensureAllCommentsPrinted(astComments, opts);
+  ensureAllCommentsPrinted(astComments);
+  // Remove added indentation after last newline
+  if (addIndents > 0) {
+    return str.trimRight() + opts.newLine;
+  }
   return str;
 }
 
+function countIndents(text, opts) {
+  const tabSpaces = ' '.repeat(opts.tabWidth);
+  const indentation = text.match(/^([ \t]*)/)[1].replace(/\t/g, tabSpaces);
+  const numIndents = Math.floor(indentation.length / opts.tabWidth);
+  return numIndents;
+}
+
 function formatWithShebang(text, opts) {
   if (!text.startsWith("#!")) {
     return format(text, opts);

diff --git a/src/printer.js b/src/printer.js
@@ -64,10 +64,7 @@ function genericPrint(path, options, printPath, args) {
   var node = path.getValue();
 
   // Escape hatch
-  if (
-    hasPrettierIgnoreComment(node) ||
-    util.isOutsideRange(node, options.rangeStart, options.rangeEnd)
-  ) {
+  if (hasPrettierIgnoreComment(node)) {
     return options.originalText.slice(util.locStart(node), util.locEnd(node));
   }
 
@@ -4251,7 +4248,7 @@ function removeLines(doc) {
   });
 }
 
-function printAstToDoc(ast, options) {
+function printAstToDoc(ast, options, addIndents = 0) {
   function printGenerically(path, args) {
     return comments.printComments(
       path,
@@ -4263,7 +4260,14 @@ function printAstToDoc(ast, options) {
 
   const doc = printGenerically(FastPath.from(ast));
   docUtils.propagateBreaks(doc);
-  return doc;
+  return addIndentsToDoc(doc, addIndents);
+}
+
+function addIndentsToDoc(doc, numIndents) {
+  if (numIndents <= 0) {
+    return doc;
+  }
+  return addIndentsToDoc(indent(doc), numIndents - 1);
 }
 
 module.exports = { printAstToDoc };
diff --git a/src/util.js b/src/util.js
@@ -320,16 +320,6 @@ function isBlockComment(comment) {
   return comment.type === "Block" || comment.type === "CommentBlock";
 }
 
-function isOutsideRange(node, rangeStart, rangeEnd) {
-  if (!node) {
-    return false;
-  }
-  const nodeStart = locStart(node);
-  const nodeEnd = locEnd(node);
-  const isOutside = nodeEnd < rangeStart || nodeStart >= rangeEnd;
-  return isOutside;
-}
-
 module.exports = {
   getPrecedence,
   isExportDeclaration,
@@ -351,6 +341,5 @@ module.exports = {
   setLocEnd,
   startsWithNoLookaheadToken,
   hasBlockComments,
-  isBlockComment,
-  isOutsideRange
+  isBlockComment
 };
diff --git a/tests/range/__snapshots__/jsfmt.spec.js.snap b/tests/range/__snapshots__/jsfmt.spec.js.snap
@@ -1,36 +1,24 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
 exports[`range.js 1`] = `
-// will NOT be formatted
-function ugly ( has , unPrettier , param,spacing) {
-
-}
-
-// will be formatted
-function ugly ( has , unPrettier , param,spacing) {
-    \`multiline template string
-     with too much indentation\`
-}
-
-// will NOT be formatted
-function ugly ( has , unPrettier , param,spacing) {
-
+function ugly ( {a=1,     b     =   2     }      ) {
+  function ugly ( {a=1,     b     =   2     }      ) {
+    function ugly ( {a=1,     b     =   2     }      ) {
+             \`multiline template string
+              with too much indentation\`
+      // The [165, 246) range selects the above two lines, including the second newline
+    }
+  }
 }
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-// will NOT be formatted
-function ugly ( has , unPrettier , param,spacing) {
-
-}
-
-// will be formatted
-function ugly(has, unPrettier, param, spacing) {
-  \`multiline template string
-     with too much indentation\`;
-}
-
-// will NOT be formatted
-function ugly ( has , unPrettier , param,spacing) {
-
+function ugly ( {a=1,     b     =   2     }      ) {
+  function ugly ( {a=1,     b     =   2     }      ) {
+    function ugly ( {a=1,     b     =   2     }      ) {
+             \`multiline template string
+              with too much indentation\`;
+      // The [165, 246) range selects the above two lines, including the second newline
+    }
+  }
 }
 
 `;
diff --git a/tests/range/jsfmt.spec.js b/tests/range/jsfmt.spec.js
@@ -1 +1 @@
-run_spec(__dirname, { rangeStart: 103, rangeEnd: 159 });
+run_spec(__dirname, { rangeStart: 165, rangeEnd: 246 });
diff --git a/tests/range/range.js b/tests/range/range.js
@@ -1,15 +1,9 @@
-// will NOT be formatted
-function ugly ( has , unPrettier , param,spacing) {
-
-}
-
-// will be formatted
-function ugly ( has , unPrettier , param,spacing) {
-    `multiline template string
-     with too much indentation`
-}
-
-// will NOT be formatted
-function ugly ( has , unPrettier , param,spacing) {
-
+function ugly ( {a=1,     b     =   2     }      ) {
+  function ugly ( {a=1,     b     =   2     }      ) {
+    function ugly ( {a=1,     b     =   2     }      ) {
+             `multiline template string
+              with too much indentation`
+      // The [165, 246) range selects the above two lines, including the second newline
+    }
+  }
 }
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		run_spec(__dirname, { rangeStart: 103, rangeEnd: 159 });
		run_spec(__dirname, { rangeStart: 165, rangeEnd: 246 });