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Schema coverage

Point ProtoTest at your GraphQL schema and it reports which types, fields, arguments and input fields your suite actually exercised.

builder.AddApplication("Api", app => app
    .AddGraphQL(graphQL => graphQL
        .AddClient("GraphQL")
        .WithSchemaCoverage(Path.Combine(AppContext.BaseDirectory, "control-plane.graphql"))));

schemaSource accepts a file path, an inline SDL string, or a URL. Leave it out to read it from configuration instead:

builder.AddApplication("Api", app => app
    .AddGraphQL(graphQL => graphQL
        .AddClient("GraphQL", "https://api.example.test/graphql")
        .WithSchemaCoverage()));
{ "ProtoTest": { "Applications": { "Api": { "GraphQL": { "Schema": "schema.graphql" } } } } }

A relative URL in Schema resolves against the application's BaseUrl. Without a schema from either source, the collector throws InvalidOperationException naming the missing GraphQL:Schema key.

Ship the schema with the tests

Copy the .graphql file to the output directory so AppContext.BaseDirectory finds it:

<None Include="control-plane.graphql" CopyToOutputDirectory="PreserveNewest" />

The collector is added by WithSchemaCoverage() or WithSchemaCoverage(schemaSource), which is shorthand for .AddCollector<GraphQLSchemaCoverageCollector>(schemaSource); the parameterless overload binds the schema from configuration instead.

What counts as covered​

Every executed document — shape-driven, fluent or raw — is parsed and walked against the schema, following fragments and inline fragments (each fragment is walked once per document). A hit is recorded for:

  • every field selected,
  • every argument passed to a field,
  • every input-object field supplied — including values that arrived through variables.

Introspection types (__Schema, __Type, …) are ignored.

Operation coverage​

GraphQLCoverageCollector is the operation-level collector that sits alongside the schema collector. Where the schema collector reports fields, arguments and input fields, this one aggregates every graphql.response observation — shape-driven, fluent, raw, or a subscription event — into one covered GraphQL operation item per operation identifier, with a hit count. Operation names are case-sensitive. Register it the same way with .AddCollector<GraphQLCoverageCollector>(); it ignores other observation kinds such as graphql.contract.shape.

What gets reported​

Items appear under the category GraphQL schema, nested like the schema:

GraphQL type          Query
└─ GraphQL field      orders            (returnType, deprecated)
   └─ GraphQL argument   where
GraphQL input type    CreateOrderInput
└─ GraphQL input field   product

Each field, argument and input-field item carries IsCovered and a hit count; fields add returnType and deprecated metadata, and arguments and input fields carry their declared type. Type rows aggregate the fields (or input fields) under them with a total hit count and no IsCovered verdict of their own — so the report also tells you whether you're still exercising deprecated fields.

The report is written by whichever sinks you register. See Coverage for the bigger picture.