Enforce GraphQL formatting conventions and best practices
GraphOS provides schema linting to help you enforce formatting conventions and other GraphQL best practices with every proposed change to your graph's schema.
- If you set up schema checks for your graph, linting runs as a separate check type alongside build and operation checks.
- You can also perform one-off linting with the Rover CLI.
GraphOS schema linting only analyzes parts of your modified schema that differ from your published schema. It does not flag any existing violations.
The GraphOS schema linter uses a predefined collection of rules to identify issues with proposed schema changes. The predefined collection includes schema composition rules. The graph-wide linter defaults you define apply to all variants of a particular graph.
To navigate to your linter configuration:
In GraphOS Studio, go to your graph's Checks page.
Click Configuration in the upper right to open the checks configuration page.
From the checks configuration page, open the Linter section:
This page organizes linter options into the following categories:
- General Linter Configuration provides high-level options, including disabling the linter entirely.
- Approved @tag names enables you to specify approved values for the
nameargument of the
@tagdirective. This directive is used most commonly with GraphOS contracts.
- If you don't use the
@tagdirective, you can ignore this category.
- Using a non-approved value for
- If you don't use the
- Rule Severity Configuration enables you to set the severity level for violations of each rule.
If you view this configuration for a single variant, each category displays a Use Graph Settings toggle in the upper right. If this toggle is enabled, the variant uses whatever graph-wide defaults are set for that category. At this time, the Use Graph Settings toggle is always enabled for all variants.
The Rules Severity Configuration category of your linter configuration displays all predefined rules and the current severity level for each:
Click a rule's severity to set it to any of the following:
- Error. Any violation of this rule causes the associated linter check to fail.
- This in turn causes the entire schema checks run to fail, which is useful for failing builds in CI.
- Warn. Violations of this rule are flagged in checks reports, but they don't cause the associated linter check to fail.
- Ignore. Violations of this rule are ignored entirely.
For information on specific rules, see the reference list of rules.
If you set up schema checks for your graph, schema linting automatically runs as a separate check type alongside build and operation checks. You can view the results of all check types from your graph's Checks page in Studio:
For the best experience running linter checks, install v0.16 or later of the Rover CLI. Earlier versions of Rover can't correctly output the results of linter checks, but they do correctly exit with a nonzero code if a linter check fails.
One-off linting requires v0.16 or later of the Rover CLI. Install the latest version.
The Rover CLI provides
subgraph lint and
graph lint commands for running the GraphOS linter against your local schema changes.
subgraph lintfor subgraphs in a supergraph.
graph lintfor monographs (not recommended).
rover subgraph lint and
rover graph lint commands validate all linter rules except for composition rules. Use
rover subgraph check or
rover supergraph compose to validate composition rules locally.
rover subgraph lint --name products --schema ./products-schema.graphql my-graph@my-variant
my-graph@my-variant in the example above is a graph ref that specifies the ID of the graph you're comparing your schema changes against, along with which variant you're comparing against.
Command options include:
Required. The path to a local
Alternatively, you can provide
If provided, the linter only flags violations that are present in the diff between your local schema and your published schema.
By default, one-off linting flags all violations in your local schema.
See this reference list of rules.