added the rules for server variables in v3

src/ruleset/v3/functions/serverVariables3.ts

@@ -0,0 +1,56 @@
+
+import { createRulesetFunction } from '@stoplight/spectral-core';
+
+import { getMissingProps, getRedundantProps, parseUrlVariables } from '../../utils';
+
+import type { IFunctionResult } from '@stoplight/spectral-core';
+
+export const serverVariables3 = createRulesetFunction<{ host: string, pathname: string; variables: Record<string, unknown> }, null>(
+  {
+    input: {
+      type: 'object',
+      properties: {
+        host: {
+          type: 'string',
+        },
+        pathname: {
+            type: 'string',
+        },
+        variables: {
+          type: 'object',
+        },
+      },
+      required: ['host', 'variables'],
+    },
+    options: null,
+  },
+  (targetVal, _, ctx) => {
+    const results: IFunctionResult[] = [];
+    const url = targetVal.host + targetVal.pathname;
+
+    const variables = parseUrlVariables(url);
+    if (variables.length === 0) return results;
+
+    const missingVariables = getMissingProps(variables, targetVal.variables);
+    if (missingVariables.length) {
+      results.push({
+        message: `Not all server's variables are described with "variables" object. Missed: ${missingVariables.join(
+          ', ',
+        )}.`,
+        path: [...ctx.path, 'variables'],
+      });
+    }
+
+    const redundantVariables = getRedundantProps(variables, targetVal.variables);
+    if (redundantVariables.length) {
+      redundantVariables.forEach(variable => {
+        results.push({
+          message: `Server's "variables" object has redundant defined "${variable}" host and pathname variable.`,
+          path: [...ctx.path, 'variables', variable],
+        });
+      });
+    }
+
+    return results;
+  },
+);

src/ruleset/v3/ruleset.ts

@@ -2,6 +2,7 @@
 
 import { AsyncAPIFormats } from '../formats';
 import { operationMessagesUnambiguity } from './functions/operationMessagesUnambiguity';
+import { serverVariables3 } from './functions/serverVariables3';
 import { pattern } from '@stoplight/spectral-functions';
 
 export const v3CoreRuleset = {
@@ -56,6 +57,20 @@ export const v3CoreRuleset = {
           match: '#\\/servers\\/', // If doesn't match, rule fails.
         },
       },
-    }
+    },
+
+    /**
+     * Server Object rules
+     */
+    'asyncapi2-server-variables': {
+      description: 'Server variables must be defined and there must be no redundant variables.',
+      message: '{{error}}',
+      severity: 'error',
+      recommended: true,
+      given: ['$.servers.*', '$.components.servers.*'],
+      then: {
+        function: serverVariables3,
+      },
+    },
   },
 };

test/ruleset/rules/v3/asyncapi3-server-variables.spec.ts

@@ -0,0 +1,179 @@
+import { testRule, DiagnosticSeverity } from '../../tester';
+
+testRule('asyncapi2-server-variables', [
+  {
+    name: 'valid case',
+    document: {
+      asyncapi: '3.0.0',
+      servers: {
+        production: {
+          host: '{sub}.stoplight.io',
+          protocol: 'https',
+          variables: {
+            sub: {},
+          },
+        },
+      },
+    },
+    errors: [],
+  },
+
+  {
+    name: 'server has not defined definition for one of the host variables',
+    document: {
+      asyncapi: '3.0.0',
+      servers: {
+        production: {
+          host: '{sub}.{anotherParam}.stoplight.io',
+          protocol: 'https',
+          variables: {
+            sub: {},
+          },
+        },
+      },
+    },
+    errors: [
+      {
+        message: 'Not all server\'s variables are described with "variables" object. Missed: anotherParam.',
+        path: ['servers', 'production', 'variables'],
+        severity: DiagnosticSeverity.Error,
+      },
+    ],
+  },
+
+  {
+    name: 'server has not defined definition for two of the host variables',
+    document: {
+      asyncapi: '3.0.0',
+      servers: {
+        production: {
+          host: '{sub}.{anotherParam1}.{anotherParam2}.stoplight.io',
+          protocol: 'https',
+          variables: {
+            sub: {},
+          },
+        },
+      },
+    },
+    errors: [
+      {
+        message:
+          'Not all server\'s variables are described with "variables" object. Missed: anotherParam1, anotherParam2.',
+        path: ['servers', 'production', 'variables'],
+        severity: DiagnosticSeverity.Error,
+      },
+    ],
+  },
+
+  {
+    name: 'server has not defined definition for pathname variables',
+    document: {
+      asyncapi: '3.0.0',
+      servers: {
+        production: {
+          host: '{sub}.stoplight.io',
+          pathname: '/{anotherParam}',
+          protocol: 'https',
+          variables: {
+            sub: {},
+          },
+        },
+      },
+    },
+    errors: [
+      {
+        message:
+          'Not all server\'s variables are described with "variables" object. Missed: anotherParam.',
+        path: ['servers', 'production', 'variables'],
+        severity: DiagnosticSeverity.Error,
+      },
+    ],
+  },
+
+  {
+    name: 'server has not defined definition for one of the host variables (in the components.servers)',
+    document: {
+      asyncapi: '3.0.0',
+      components: {
+        servers: {
+          production: {
+            host: '{sub}.{anotherParam}.stoplight.io',
+            protocol: 'https',
+            variables: {
+              sub: {},
+            },
+          },
+        },
+      },
+    },
+    errors: [
+      {
+        message: 'Not all server\'s variables are described with "variables" object. Missed: anotherParam.',
+        path: ['components', 'servers', 'production', 'variables'],
+        severity: DiagnosticSeverity.Error,
+      },
+    ],
+  },
+
+  {
+    name: 'server has redundant host variables',
+    document: {
+      asyncapi: '3.0.0',
+      servers: {
+        production: {
+          host: '{sub}.stoplight.io',
+          protocol: 'https',
+          variables: {
+            sub: {},
+            anotherParam1: {},
+            anotherParam2: {},
+          },
+        },
+      },
+    },
+    errors: [
+      {
+        message: 'Server\'s "variables" object has redundant defined "anotherParam1" host and pathname variable.',
+        path: ['servers', 'production', 'variables', 'anotherParam1'],
+        severity: DiagnosticSeverity.Error,
+      },
+      {
+        message: 'Server\'s "variables" object has redundant defined "anotherParam2" host and pathname variable.',
+        path: ['servers', 'production', 'variables', 'anotherParam2'],
+        severity: DiagnosticSeverity.Error,
+      },
+    ],
+  },
+
+  {
+    name: 'server has redundant host variables (in the components.servers)',
+    document: {
+      asyncapi: '3.0.0',
+      components: {
+        servers: {
+          production: {
+            host: '{sub}.stoplight.io',
+            protocol: 'https',
+            variables: {
+              sub: {},
+              anotherParam1: {},
+              anotherParam2: {},
+            },
+          },
+        },
+      },
+    },
+    errors: [
+      {
+        message: 'Server\'s "variables" object has redundant defined "anotherParam1" host and pathname variable.',
+        path: ['components', 'servers', 'production', 'variables', 'anotherParam1'],
+        severity: DiagnosticSeverity.Error,
+      },
+      {
+        message: 'Server\'s "variables" object has redundant defined "anotherParam2" host and pathname variable.',
+        path: ['components', 'servers', 'production', 'variables', 'anotherParam2'],
+        severity: DiagnosticSeverity.Error,
+      },
+    ],
+  },
+]);