json_schema_passes

Validate every JSON / YAML / TOML / XML / dotenv / properties / INI / HCL file in paths against a JSON Schema document. Targets coerce through serde into the same serde_json::Value tree the schema sees, so a JSON-format schema can validate a YAML config (Kubernetes manifests, GitHub Actions workflows, Helm values.schema.json) or a TOML manifest (Cargo.toml, pyproject.toml) without separate schemas per format. The schema is loaded + compiled lazily on first evaluation and cached on the rule. XML / .properties / INI leaves and assigned dotenv values are strings, so type those fields as string (with a pattern) — integer / boolean / number assertions fail against them. A dotenv bare declaration maps to JSON null. JSON / YAML / TOML / HCL keep native types.

Each schema-validation mismatch becomes one policy violation, with the failing instance path and the schema's error description in the message. A target that fails to parse produces one non-baselinable resource_parse analysis failure, not a flood of schema errors against junk. An unreadable or malformed schema likewise produces one resource_read or resource_parse analysis failure. Format is detected from the target's extension (.json / .yaml / .yml / .toml / .properties / .ini / .cfg / .hcl / .tf / .tfvars / .nomad / .xml and the .csproj / .props / .targets family), or by filename for the .env family; pass format: to override.

Check-only — fixing schema violations is a "the user knows what value belongs there" problem, not alint's.

Options

Option	Type	Required	Default	Description
`format`	one of `json` \| `yaml` \| `yml` \| `toml` \| `xml` \| `dotenv` \| `properties` \| `ini` \| `hcl`			Override the auto-detected target format. When omitted, format is inferred from each target file's extension (.json / .yaml / .yml / .toml / .properties / .ini / .cfg / .hcl / .tf / .tfvars / .nomad / .xml and the .csproj / .props / .targets XML family), or by filename for the `.env` family.
`schema_path`	string	yes		Path to a JSON Schema file relative to the lint root. The schema must itself be JSON even when validating YAML / TOML targets.

Plus the common paths, level, id, when, scope_filter, and expect_matches fields. This table is generated from the JSON Schema; option types and defaults are authoritative.

Example

A package.json that violates its JSON Schema

The rule fires on this repository:

package.json
✗ error package-conforms
schema violation at `/version`: "v1.x" does not match "^[0-9]+\.[0-9]+\.[0-9]+$"
schemas/
schemas/package.schema.json✓

{
  "name": "demo",
  "version": "v1.x"
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "required": ["name", "version"],
  "properties": {
    "name": {"type": "string"},
    "version": {"type": "string", "pattern": "^[0-9]+\\.[0-9]+\\.[0-9]+$"}
  }
}

With this .alint.yml:

version: 1
rules:
  - id: package-conforms
    kind: json_schema_passes
    paths: "package.json"
    schema_path: "schemas/package.schema.json"
    level: error

alint check reports:

--- package.json ---------------------------------------------------------------
  x  error    package-conforms
              schema violation at `/version`: "v1.x" does not match
              "^[0-9]+\.[0-9]+\.[0-9]+$"

Summary (1 violation):
  x 1 error
  0 passing * 1 failing

A .csproj auto-detected as XML that violates its JSON Schema

The rule fires on this repository:

App.csproj
✗ error csproj-conforms
schema violation at `/Project/PropertyGroup/TargetFramework`: "banana" does not match "^net[0-9]+\.[0-9]+$"
schemas/
schemas/project.schema.json✓

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>banana</TargetFramework>
  </PropertyGroup>
</Project>

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "required": ["Project"],
  "properties": {
    "Project": {
      "type": "object",
      "required": ["@Sdk", "PropertyGroup"],
      "properties": {
        "@Sdk": {"type": "string"},
        "PropertyGroup": {
          "type": "object",
          "required": ["TargetFramework"],
          "properties": {
            "TargetFramework": {"type": "string", "pattern": "^net[0-9]+\\.[0-9]+$"}
          }
        }
      }
    }
  }
}

With this .alint.yml:

version: 1
rules:
  - id: csproj-conforms
    kind: json_schema_passes
    paths: "App.csproj"
    schema_path: "schemas/project.schema.json"
    level: error

alint check reports:

--- App.csproj -----------------------------------------------------------------
  x  error    csproj-conforms
              schema violation at `/Project/PropertyGroup/TargetFramework`:
              "banana" does not match "^net[0-9]+\.[0-9]+$"

Summary (1 violation):
  x 1 error
  0 passing * 1 failing

A package.json that conforms to its JSON Schema

This repository is compliant:

package.json✓
schemas/
schemas/package.schema.json✓

{
  "name": "demo",
  "version": "1.2.3"
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "required": ["name", "version"],
  "properties": {
    "name": {"type": "string"},
    "version": {"type": "string", "pattern": "^[0-9]+\\.[0-9]+\\.[0-9]+$"}
  }
}

With this .alint.yml:

version: 1
rules:
  - id: package-conforms
    kind: json_schema_passes
    paths: "package.json"
    schema_path: "schemas/package.schema.json"
    level: error

alint check reports:

v All 1 rule(s) passed.

An explicit format xml parses an .config file that conforms to the schema

This repository is compliant:

app.config✓
schemas/
schemas/project.schema.json✓

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
  </PropertyGroup>
</Project>

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "required": ["Project"],
  "properties": {
    "Project": {
      "type": "object",
      "required": ["@Sdk", "PropertyGroup"],
      "properties": {
        "@Sdk": {"type": "string"},
        "PropertyGroup": {
          "type": "object",
          "required": ["TargetFramework"],
          "properties": {
            "TargetFramework": {"type": "string", "pattern": "^net[0-9]+\\.[0-9]+$"}
          }
        }
      }
    }
  }
}

With this .alint.yml:

version: 1
rules:
  - id: config-conforms
    kind: json_schema_passes
    paths: "app.config"
    schema_path: "schemas/project.schema.json"
    format: xml
    level: error

alint check reports:

v All 1 rule(s) passed.