Package: fdiff
An OpenType table diff tool for fontsAboutfdiffis a Python command line comparison tool for assessment of granular differences in the OpenType table data between font files.  The tool provides cross-platform support for local and remote font diffs on macOS, Windows, and GNU/Linux systems with a Python v3.6+ interpreter.Looking for a high-level overview of OpenType table differences rather than low-level changes?  Check out Just van Rossum'sfbdifftool.What it doesTakes two font file path arguments (or URL for remote fonts) for the font comparisonDumps OpenType table data in the fontTools library TTX format (XML)Compares the OpenType table data across the two files using the unified diff format with 3 lines of surrounding contextOptional FeaturesFilter OpenType tables with the--includeor--excludeoptionsModify the number of context lines displayed in the diff with the-lor--linesoptionDisplay the first n lines of the diff output with the--headoptionDisplay the last n lines of the diff output with the--tailoptionExecute the diff with an external diff tool using the--externaloptionRunfdiff --helpto view all available options.ContentsInstallationUsageIssuesContributingAcknowledgmentsLicenseInstallationfdiffrequires a Python 3.6+ interpreter.Installation in aPython3 virtual environmentis recommended.Use any of the following installation approaches:pip install from PyPI$ pip3 install fdiffpip install from source$ git clone https://github.com/source-foundry/fdiff.git
$ cd fdiff
$ pip3 install -r requirements.txt .Developer install from sourceThe following approach installs the project and associated optional developer dependencies, so that source changes are available without the need for re-installation.$ git clone https://github.com/source-foundry/fdiff.git
$ cd fdiff
$ pip3 install --ignore-installed -r requirements.txt -e ".[dev]"UsageLocal font files$ fdiff [OPTIONS] [PRE-FONT FILE PATH] [POST-FONT FILE PATH]Remote font filesfdiffsupports GET requests for publicly accessible remote font files.  Replace the file path arguments with URL:$ fdiff [OPTIONS] [PRE-FONT FILE URL] [POST-FONT FILE URL]fdiffworks with any combination of local and remote font files. For example, to compare a local post font file with a remote pre font file to assess local changes against a font file that was previously pushed to a remote, use the following syntax:$ fdiff [OPTIONS] [PRE-FONT FILE URL] [POST-FONT FILE FILE PATH]⭐Tip: Remote git repository hosting services (like Github) support access to files on different git branches by URL.  Use these repository branch URL to compare fonts across git branches in your repository.OptionsFilter OpenType tablesTo include only specified tables in your diff, use the--includeoption with a comma-separated list of table names:$ fdiff --include head,post [PRE-FONT FILE PATH] [POST-FONT FILE PATH]To exclude specified tables in your diff, use the--excludeoption with a comma-separated list of table names:$ fdiff --exclude glyf,OS/2 [PRE-FONT FILE PATH] [POST-FONT FILE PATH]Do not include spacesbetween the comma-separated table name values!Change number of context linesTo change the number of lines of context above/below lines that have differences, use the-lor--linesoption with an integer value for the desired number of lines.  The following command reduces the contextual information to a single line above and below lines with differences:$ fdiff -l 1 [PRE-FONT FILE PATH] [POST-FONT FILE PATH]Display the first n lines of outputUse the--headoption followed by an integer for the number of lines at the beginning of the output.  For example, the following command displays the first 20 lines of the diff:$ fdiff --head 20 [PRE-FONT FILE PATH] [POST-FONT FILE PATH]Display the last n lines of outputUse the--tailoption followed by an integer for the number of lines at the end of the output.  For example, the following command displays the last 20 lines of the diff:$ fdiff --tail 20 [PRE-FONT FILE PATH] [POST-FONT FILE PATH]Use an external diff toolPlease Note: This feature has not been tested across all supported platforms.  Please report any issues that you come across on the project issue tracker.By default, fdiff performs diffs with Python source.  If you run into performance issues with this approach, you can use compiled diff executables that are available on your platform.  fdiff will dump the ttx files and run the command that you provide on the command line passing the pre and post font ttx dump file paths as the first and second positional arguments to your command.For example, you may run thediff -ucommand on GNU/Linux or macOS like this:$ fdiff --external="diff -u" [PRE-FONT FILE PATH] [POST-FONT FILE PATH]fdiff supports built-in color formatting and OpenType table filtering when used with external diff tools.  The context line, head, and tail options are not supported with the use of external diff tools.Disable color diffsANSI escape code colored diffs are performed by default in terminal environments.To view a diff without ANSI escape codes in your terminal, include the--nocoloroption in your command:$ fdiff --nocolor [PRE-FONT FILE PATH] [POST-FONT FILE PATH]Other OptionsUsefdiff -hto view all available options.IssuesPlease report issues on theproject issue tracker.ContributingContributions are warmly welcomed.  A development dependency environment can be installed in editable mode with the developer installation documentation above.Please use the standard Github pull request approach to propose source changes.Source file lintingPython source files are linted withflake8.  See the Makefiletest-linttarget for details.TestingThe project runs continuous integration testing on the GitHub Actions service with thepytesttoolchain.  Test modules are located in thetestsdirectory of the repository.Local testing by Python interpreter version can be performed with the following command executed from the root of the repository:$ tox -e [PYTHON INTERPRETER VERSION]Please see thetoxdocumentation for additional details.Test coverageUnit test coverage is executed with thecoveragetool.  See the Makefiletest-coveragetarget for details.Acknowledgmentsfdiffis built with the fantasticfontTools free software libraryand performs text diffs of binary font files using dumps of the TTX OpenType table data serialization format as defined in the fontTools library.LicenseCopyright 2019 Source Foundry Authors and ContributorsLicensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License athttp://www.apache.org/licenses/LICENSE-2.0Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.