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    4.0.0 • Public • Published


    Node JS directory compare

    !! Important !! Starting with v3.0.0 the CLI utility has been moved to dir-compare-cli.

    Build status


    npm install dir-compare



    const dircompare = require('dir-compare');
    const options = { compareSize: true };
    // Multiple compare strategy can be used simultaneously - compareSize, compareContent, compareDate, compareSymlink.
    // If one comparison fails for a pair of files, they are considered distinct.
    const path1 = '...';
    const path2 = '...';
    // Synchronous
    const res = dircompare.compareSync(path1, path2, options)
    // Asynchronous, path2, options)
      .then(res => print(res))
      .catch(error => console.error(error));
    function print(result) {
      console.log('Directories are %s', result.same ? 'identical' : 'different')
      console.log('Statistics - equal entries: %s, distinct entries: %s, left only entries: %s, right only entries: %s, differences: %s',
        result.equal, result.distinct, result.left, result.right, result.differences)
      result.diffSet.forEach(dif => console.log('Difference - name1: %s, type1: %s, name2: %s, type2: %s, state: %s',
        dif.name1, dif.type1, dif.name2, dif.type2, dif.state))


    import { compare, compareSync, Options, Result } from "dir-compare";
    const path1 = '...';
    const path2 = '...';
    const options: Options = { compareSize: true };
    const res: Result = compareSync(path1, path2, options);
    compare(path1, path2, options)
      .then(res => console.log(res))
      .catch(error => console.error(error));


    compare(path1: string, path2: string, options?: Options): Promise<Result>
    compareSync(path1: string, path2: string, options?: Options): Result

    More details can be found in the reference documentation:

    Common options:

    Glob patterns

    Minimatch patterns are used to include/exclude files to be compared.

    The pattern is matched against the relative path of the entry being compared.

    Following examples assume we are comparing two dir-compare code bases.

    const options = { 
      excludeFilter: ".git,node_modules",   //  exclude git and node modules directories  
      excludeFilter: "expected"         ,   //  exclude '/tests/expected' directory  
      excludeFilter: "/tests/expected"  ,   //  exclude '/tests/expected' directory  
      excludeFilter: "**/expected"      ,   //  exclude '/tests/expected' directory  
      excludeFilter: "**/tests/**/*.js" ,   //  exclude all js files in '/tests' directory and subdirectories  
      includeFilter: "*.js,*.yml"       ,   //  include js and yaml files  
      includeFilter: "/tests/**/*.js"   ,   //  include all js files in '/tests' directory and subdirectories  
      includeFilter: "**/tests/**/*.ts"     //  include all js files in '/tests' directory and subdirectories  

    Custom file content comparators

    By default file content is binary compared. As of version 1.5.0 custom file comparison handlers may be specified.

    Custom handlers are specified by compareFileSync and compareFileAsync options which correspond to dircompare.compareSync() or methods.

    A couple of handlers are included in the library:

    • binary sync compare - dircompare.fileCompareHandlers.defaultFileCompare.compareSync
    • binary async compare - dircompare.fileCompareHandlers.defaultFileCompare.compareAsync
    • text sync compare - dircompare.fileCompareHandlers.lineBasedFileCompare.compareSync
    • text async compare - dircompare.fileCompareHandlers.lineBasedFileCompare.compareAsync

    Use defaultFileCompare.js as an example to create your own.

    Ignore line endings and white spaces

    Line based comparator can be used to ignore line ending and white space differences.

    const dircompare = require('dir-compare');
    const options = {
      compareContent: true,
      compareFileSync: dircompare.fileCompareHandlers.lineBasedFileCompare.compareSync,
      compareFileAsync: dircompare.fileCompareHandlers.lineBasedFileCompare.compareAsync,
      ignoreLineEnding: true,      // Ignore crlf/lf line ending differences
      ignoreWhiteSpaces: true,     // Ignore white spaces at the beginning and ending of a line (similar to 'diff -b')
      ignoreAllWhiteSpaces: true,  // Ignore all white space differences (similar to 'diff -w')
      ignoreEmptyLines: true       // Ignores differences caused by empty lines (similar to 'diff -B')
    const path1 = '...';
    const path2 = '...';
    const res = dircompare.compareSync(path1, path2, options);
    console.log(res), path2, options)
    .then(res => console.log(res))

    Custom name comparators

    If default name comparison is not enough, custom behavior can be specified with compareNameHandler option. Following example adds the possibility to ignore file extensions.

    import { Options, compare } from 'dir-compare'
    import path from 'path'
    const options: Options = {
        compareSize: false,                    // compare only name by disabling size and content criteria
        compareContent: false,
        compareNameHandler: customNameCompare, // new name comparator used to ignore extensions
        ignoreExtension: true,                 // supported by the custom name compare below
    function customNameCompare(name1: string, name2: string, options: Options) {
        if (options.ignoreCase) {
            name1 = name1.toLowerCase()
            name2 = name2.toLowerCase()
        if (options.ignoreExtension) {
            name1 = path.basename(name1, path.extname(name1))
            name2 = path.basename(name2, path.extname(name2))
        return ((name1 === name2) ? 0 : ((name1 > name2) ? 1 : -1))
    const path1 = '/tmp/a';
    const path2 = '/tmp/b';
    const res = compare(path1, path2, options).then(res => {
        console.log(`Same: ${res.same}`)
        if (!res.diffSet) {
        res.diffSet.forEach(dif => console.log(`${dif.name1} ${dif.name2} ${dif.state}`))
    // Outputs
    // icon.svg icon.png equal
    // logo.svg logo.jpg equal

    Custom result builder

    Result builder is called for each pair of entries encountered during comparison. Its purpose is to append entries in diffSet and eventually update statistics object with new stats.

    If needed it can be replaced with custom implementation.

    const dircompare = require("dircompare")
    const customResultBuilder = function (entry1, entry2, state, level, relativePath, options, statistics, diffSet, reason) {
    const options = {
        compareSize: true,
        resultBuilder: customResultBuilder
    const res = dircompare.compareSync('...', '...', options)

    The default builder can be used as an example.

    Symbolic links

    Unless compareSymlink option is used, symbolic links are resolved and any comparison is applied to the file/directory they point to.

    Circular loops are handled by breaking the loop as soon as it is detected.

    Version 1.x treats broken links as ENOENT: no such file or directory.
    Since 2.0 they are treated as a special type of entry - broken-link - and are available as stats (totalBrokenLinks, distinctBrokenLinks, ...).

    Using compareSymlink option causes dircompare to check symlink values for equality. In this mode two entries with identical name are considered different if

    • one is symlink, the other is not
    • both are symlinks but point to different locations

    These rules are applied in addition to the other comparison modes; ie. by content, by size...

    If entries are different because of symlinks, reason will be different-symlink. Also statistics summarizes differences caused by symbolik links.

    Handling permission denied errors

    Unreadable files or directories are normally reported as errors. The comparison will be intrerrupted with an EACCES exception. This behavior can be altered with Options.handlePermissionDenied.

    UI tools


    • v4.0.0

      • Switched project to typescript
      • Async comparator improvements when comparing large directory structures
        • Heap usage has decreased 3x compared to previous version
        • Works 2x faster when comparing by content
        • Better concurrency. UI apps will be more responsive while comparison is ongoing

      Breaking changes:

      • Using this library to compare two files will ignore the name of the files. More details in #48
      • Removed support for node 8, 9
    • v3.3.0 Added skipEmptyDirs option

    • v3.2.0 Handle permission denied errors

    • v3.1.0 Added ignoreAllWhiteSpaces and ignoreEmptyLines options

    • v3.0.0 Moved CLI component into separate project dir-compare-cli

    • v2.4.0 New option to customize file/folder name comparison

    • v2.3.0 Fixes

    • v2.1.0 Removed bluebird dependency

    • v2.0.0

      • New option to compare symlinks.
      • New field indicating reason for two entries being distinct.
      • Improved command line output format.
      • Tests are no longer part of published package.
      • Generated Api documentation.

      Breaking changes:

      • Broken links are no longer treated as errors. As a result there are new statistics (leftBrokenLinks, rightBrokenLinks, distinctBrokenLinks, totalBrokenLinks) and new entry type - broken-link. Details in Symbolic links.
      • Typescript correction: new interface Result replaced Statistics.
    • v1.8.0

      • globstar patterns
      • typescript corrections
      • removed support for node 0.11, 0.12, iojs
    • v1.7.0 performance improvements

    • v1.6.0 typescript support

    • v1.5.0 added option to ignore line endings and white space differences

    • v1.3.0 added date tolerance option

    • v1.2.0 added compare by date option

    • v1.1.0

      • detect symlink loops
      • improved color scheme for command line utility
    • v1.0.0

      • asynchronous comparison
      • new library options: noDiffSet, resultBuilder
      • new statistics: distinctFiles, equalFiles, leftFiles, rightFiles, distinctDirs, equalDirs, leftDirs, rightDirs
      • new --async command line option
      • Fix for
    • v0.0.3 Fix fille ordering issue for newer node versions


    npm i dir-compare

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    • gliviu