WebStorm 2018.2 Help

Code Inspection

Code analysis basics

WebStorm features robust, fast, and flexible static code analysis. It detects the language and runtime errors, suggests corrections and improvements .

WebStorm performs code analysis by applying inspections to your code. Numerous code inspections exist for and for the other supported languages.

The inspections detect not only compiling errors, but also different code inefficiencies. Whenever you have some unreachable code, unused code, non-localized string, unresolved method, memory leaks or even spelling problems – you'll find it very quickly.

WebStorm's code analysis is flexibly configurable. You can enable/disable each code inspection and change its severity, create profiles with custom sets of inspections, apply inspections differently in different scopes, suppress inspections in specific pieces of code, and more.

The analysis can be performed in several ways:

  • By default, WebStorm analyses all open files and highlights all detected code issues right in the editor. On the right side of the editor you can see the analysis status of the whole file (the icon in the top-right corner).

    When an error is detected, this icon is icons general balloonError svg; in case of a warning, it is warning; if everything is correct, the icon is ok.

  • Alternatively, you can run code analysis in a bulk mode for the specified scope, which can be as large as the whole project.

  • If necessary, you can apply a single code inspection in a specific scope.

For the majority of the detected code issues, WebStorm provides quick fix suggestions. You can quickly review errors in a file by navigating from one highlighted line to another by pressing F2Shift+F2.

For more information and procedural descriptions, see Configuring Inspection Severities.

Inspection profiles

When you inspect your code, you can tell WebStorm which types of problems you would like to search for and get reports about. Such configurations can be preserved as inspection profiles.

An inspection profile defines the types of problems to be sought for, i.e. which code inspections are enabled/disabled and the severity of these inspections. Profiles are configurable in the Inspections settings page.

To set the current inspection profile (the one that is used for the on-the-fly code analysis in the editor), simply select it in the Inspections settings page and apply changes. When you perform code analysis or execute a single inspection, you can specify which profile to use for each run.

Inspection profiles can be applicable for the entire IDE or for a specific project:

  • Project profiles are shared and accessible for the team members via VCS. They are stored in the project directory: <project>/.idea/inspectionProfiles.

  • IDE profiles are intended for personal use only and are stored locally in XML files under the USER_HOME/.<WebStorm version>/config/inspection directory.

WebStorm comes with the following pre-defined inspection profiles:

  • Default: This local (IDE level) profile is intended for personal use, applies to all projects, and is stored locally in the Default.xml file under the USER_HOME/.<WebStorm version>/config/inspection directory.

  • Project Default: when a new project is created, the Project Default profile is copied from the settings of a template project. This profile is shared and applies to the current project.
    After a project is created, any modifications to the project default profile will pass unnoticed to any other projects.
    When the settings of the Project Default profile are modified in the Template Project settings, the changed profile will apply to all newly created projects, but the existing projects will not be affected as they already have a copy of this profile.
    Project Default profile is stored in the Project_Default.xml file located in the <project>/.idea/inspectionProfiles directory.

One can have as many inspection profiles as required. There are two ways of creating new profiles: you can add a new profile as a copy of the Project Default profile or copy the currently selected profile. The newly created profiles are stored in XML files, located depending on the type of the base profile.

The <profile_name>.xml files representing inspection profiles appear whenever some changes to the profiles are done and applied. The files only store differences against the default profile.

Refer to the section Customizing Profiles for details.

Synchronizing profiles between computers

If an inspection profile is made project-specific, it is synchronized with your project automatically. Each user, who opens this project after checking it out, will have the same inspection profile enabled.

If an IDE Default inspection profile is used, it can be synchronized between multiple machines via the Settings Repository plugin, bundled with WebStorm. So doing, the file is stored in USER_HOME/.<WebStorm version>/config/inspection/<profile_name>.xml.

Note that the Global profile may have a different name. Copy your current project profile to the Global Level (click the button Manage and choose Copy as Global) and call it as you like.

Then, on the main menu, choose File | Settings for New Projects and select this global profile as the default one for all the new projects. Now all the newly-created projects will use this global profile by default and this global profile will be synchronized between the various machines via the Settings Repository plugin.

Inspection severity

Inspection severity indicates how seriously the code issues detected by the inspection impact the project and determines how the detected issues should be highlighted in the editor. By default, each inspection has one of the following severity levels:

  • Server problem server problem

  • Typo typo

  • No highlighting, only fix info

  • Weak Warning weak warning

  • Warning warning

  • Error error

You can increase or decrease the severity level of each inspection. That is, you can force WebStorm to display some warnings as errors or weak warnings. In a similar way, what is initially considered a weak warning can be displayed as a warning or error, or just as info.

You can also configure the color and font style used to highlight each severity level. Besides, you can create custom severity levels and set them for specific inspections.

If necessary, you can set different severity levels for the same inspection in different scopes.

All modifications to inspections mentioned above are saved in the inspection profile currently selected in the inspection settings and apply when this profile is used.

Inspection scope

By default, all enabled code inspections apply to all project files. If necessary, you can configure each code inspection (enable/disable, change its severity level and options) individually for different scopes. Such configurations, like any other inspection settings, are saved and applied as part of a specific profile.

There may be complicated cases when an inspection has different configurations associated with different scopes. When such inspection is executed in a file belonging to some or all of these scopes, the settings of the highest priority scope-specific configuration are applied. The priorities are defined by the relative position of the inspection's scope-specific configuration in inspection settings: the uppermost configuration has the highest priority. The Everywhere else configuration always has the lowest priority.

For more information and procedural descriptions, see Configuring Inspection for Different Scopes.

Examples of code inspections

In the Inspections page, all inspections are grouped into categories. The most common tasks covered by code analysis are:

  • Locating dead code.

  • Detecting performance issues.

  • Improving code structure and maintainability.

  • Conforming to coding guidelines and standards.

  • Conforming to specifications.

Locating dead code

WebStorm highlights in the editor pieces of so-called dead code. This is the code that is never executed during the application runtime. Perhaps, you don't even need this part of code in your project. Depending on situation, such code may be treated as a bug or as a redundancy. Anyway it decreases the application performance and complicates the maintenance process. Here is an example.

So-called constant conditions - conditions that are never met or are always true, for example. In this case the responsible code is not reachable and actually is a dead code.

code locating

WebStorm highlights the if condition as it's always true. So the part of code surrounded with else is actually a dead code because it is never executed.

Highlighting unused declarations

WebStorm is also able to instantly highlight Java classes, methods and fields which are unused across the entire project via Unused declarations inspection. All sorts of Java EE @Inject annotations, test code entry points and other implicit dependencies configured in the Unused declarations inspection are deeply respected.

Unresolved JavaScript function or method

This inspection detects references to undefined JavaScript functions or methods.

js unresolved function or method
Last modified: 19 November 2018

See Also