IntelliJ Plugin: Exact file type matcher

README.md

While writing IntelliJ Idea Plugin how to map the exact file name.

For example, you want to write a plugin for files exactly named abc.json, or in more practical scenarios Jenkinsfile

1. Write FileMatcherType class

 class MyFileType extends LanguageFileTyp {
    public static final MyFileType INSTANCE = new MyFileType();

    private MyFileType() {
        super(MyLanguage.INSTANCE);
    }

    @NotNull
    @Override
    public String getName() {
        return "My File";
    }

    @NotNull
    @Override
    public String getDescription() {
        return "My language file";
    }

    @NotNull
    @Override
    public String getDefaultExtension() {
        return "json";
    }

    @Nullable
    @Override
    public Icon getIcon() {
        return MyLanguageIcons.FILE;
    }
}

Now, in your plugin.xml, add following lines

    <extensions defaultExtensionNs="com.intellij">
        <fileType implementationClass="MyFileType" fileNames="abc.json" name="My File"
                  fieldName="INSTANCE" language="My Language"/>
    </extensions>

Now, here it's bit odd that in getDefaultExtension we write json and in plugin.xml we write fileNames="abc.json". But this works.