add: new checks syntax highlighting

examples/main.tf

@@ -20,3 +20,14 @@ module "vpc" {
 
   tags = local.tags
 }
+
+check "health_check" {
+  data "http" "terraform_io" {
+    url = "https://www.terraform.io"
+  }
+
+  assert {
+    condition = data.http.terraform_io.status_code == 200
+    error_message = "${data.http.terraform_io.url} returned an unhealthy status code"
+  }
+}

grammars/tf.yaml

@@ -208,6 +208,42 @@ patterns:
           1: { name: support.output.attribute.tf }
           2: { name: keyword.operator.assignment.tf }
       - include: "#definition-right"
+
+  - name: "meta.check.tf"
+    begin: '\b(check)([\w\-\"$])?(?:\s+)?(")?([^\"\n]+)?(")?(?:\s+)?({)'
+    beginCaptures:
+      1: { name: keyword.declaration.$1.tf }
+      2: { name: invalid.illegal.keyword.$1.tf }
+      3:
+        { name: string.quoted.double.tf punctuation.definition.string.begin.tf }
+      4: { name: string.quoted.double.tf entity.name.$1.tf }
+      5: { name: string.quoted.double.tf punctuation.definition.string.end.tf }
+      6: { name: punctuation.declaration.block.begin.tf }
+    end: "}"
+    endCaptures:
+      0: { name: punctuation.declaration.block.end.tf }
+    patterns:
+      - include: "#comments"
+      - match: '\b(data)(?:\s+)?(=)?(?:\s+)?'
+        captures:
+          1: { name: keyword.declaration.$1.tf }
+          2: { name: invalid.illegal.keyword.$1.tf }
+          3:
+            { name: string.quoted.double.tf punctuation.definition.string.begin.tf }
+          4: { name: string.quoted.double.tf entity.type.$1.tf }
+          5: { name: string.quoted.double.tf punctuation.definition.string.end.tf }
+          6:
+            { name: string.quoted.double.tf punctuation.definition.string.begin.tf }
+          7: { name: string.quoted.double.tf entity.name.$1.tf }
+          8: { name: string.quoted.double.tf punctuation.definition.string.end.tf }
+          9: { name: punctuation.declaration.block.begin.tf }
+      - match: '\b(assert)(?:\s+)?(=)?(?:\s+)?'
+        captures:
+          1: { name: meta.keyword.$1.tf }
+          2: { name: keyword.operator.assignment.tf }
+      - include: "#definition-right"
+      - match: '\S'
+        name: invalid.illegal.keyword.variable.tf
 
   - name: "meta.data.tf"
     begin: '\b(data)([\w\-\"$])?(?:\s+)?(")?([^\"\n]+)?(")?(?:\s+)?(")?([^\"\n]+)?(")?(?:\s+)?({)'

snippets/tf.yaml

@@ -142,6 +142,23 @@ Data http:
       }
     }
 
+Check http:
+Variable:
+  scope: source.tf
+  prefix: check-http
+  description: Input variable.
+  body: |
+    check ${1:name} {
+      data http ${2:name} {
+        url = ${3|"https://","http://",var.,data.,local.,module.|}
+      }
+
+      assert {
+        condition = ${4:boolean_expression}
+        error_message = ${5:error_string}
+      }
+    }
+
 # --- Provider: Terraform
 
 Data from remote terraform state: