Adding unset attr rule

.vale/fixtures/AsciiDoc/UnsetAttributes/.vale.ini

@@ -0,0 +1,5 @@
+; Vale configuration file to test the `UnsetAttributes` rule
+StylesPath = ../../../styles
+MinAlertLevel = error
+[*.adoc]
+AsciiDoc.UnsetAttributes = YES

.vale/fixtures/AsciiDoc/UnsetAttributes/testinvalid.adoc

@@ -0,0 +1,15 @@
+:context: creating-infrastructure-machinesets
+
+ifeval::["{context}" == "creating-infrastructure-machinesets"]
+:infra:
+endif::[]
+
+Vale reports lots of errors, it should also report an attribute that you forgot to unset
+
+////
+Ignore multi-line comments
+:!infra:
+////
+
+//ignore comments
+//:!infra:

.vale/fixtures/AsciiDoc/UnsetAttributes/testvalid.adoc

@@ -0,0 +1,19 @@
+:context: creating-infrastructure-machinesets
+
+ifeval::["{context}" == "creating-infrastructure-machinesets"]
+//vale-fixture
+:infra:
+endif::[]
+
+Vale reports lots of errors, it should also report an attribute that you forgot to unset
+
+ifeval::["{context}" == "creating-infrastructure-machinesets"]
+//vale-fixture
+:!infra:
+endif::[]
+
+//This is really just unsetting a second time, but it should not trip the rule
+ifeval::["{context}" == "creating-infrastructure"]
+//vale-fixture
+:infra!:
+endif::[]

.vale/styles/AsciiDoc/UnsetAttributes.yml

@@ -0,0 +1,42 @@
+---
+extends: script
+level: error
+message: "Set attribute has not been unset in the current file."
+link: https://docs.asciidoctor.org/asciidoc/latest/attributes/unset-attributes/#unset-a-document-attribute-in-the-header
+scope: raw
+script: |
+  text := import("text")
+  matches := []
+
+  // trim extra whitespace
+  scope = text.trim_space(scope)
+  // add a newline, it might be missing
+  scope += "\n"
+  // clean out multi-line comments
+  scope = text.re_replace("(?s) *(\n////.*?////\n)", scope, "")
+
+  attr_regex := "^:[\\w-]+:$"
+  unset_attr_pref := ""
+  unset_attr_suff := ""
+
+  for line in text.split(scope, "\n") {
+    if text.re_match(attr_regex, line) {
+      start := text.index(scope, line)
+      matches = append(matches, {begin: start, end: start + len(line)})
+      unset_attr_pref = `^:!` + text.trim_prefix(line, `:`)
+      unset_attr_suff = `^` + text.trim_suffix(line, `:`) + `!:`
+      // loop through lines for every attr found
+      for line in text.split(scope, "\n") {
+        if text.re_match(unset_attr_pref, line) {
+          if len(matches) > 0 {
+            // remove the most recently added match
+            matches = matches[:len(matches)-1]
+          } else if text.re_match(unset_attr_suff, line) {
+            if len(matches) > 0 {
+              matches = matches[:len(matches)-1]
+            }
+          }
+        }
+      }
+    }
+  }

tengo-rule-scripts/UnsetAttributes.tengo

@@ -0,0 +1,51 @@
+/*
+Tengo Language
+$ tengo UnsetAttributes.tengo <asciidoc_file_to_validate>
+*/
+
+fmt := import("fmt")
+os := import("os")
+text := import("text")
+
+input := os.args()
+scope := os.read_file(input[2])
+matches := []
+
+// trim extra whitespace
+scope = text.trim_space(scope)
+// add a newline, it might be missing
+scope += "\n"
+// clean out multi-line comments
+scope = text.re_replace("(?s) *(\n////.*?////\n)", scope, "")
+
+attr_regex := "^:[\\w-]+:$"
+unset_attr_pref := ""
+unset_attr_suff := ""
+
+for line in text.split(scope, "\n") {
+  if text.re_match(attr_regex, line) {
+    start := text.index(scope, line)
+    matches = append(matches, {begin: start, end: start + len(line)})
+    unset_attr_pref = `^:!` + text.trim_prefix(line, `:`)
+    unset_attr_suff = `^` + text.trim_suffix(line, `:`) + `!:`
+    // loop through lines for every attr found
+    for line in text.split(scope, "\n") {
+      if text.re_match(unset_attr_pref, line) {
+        if len(matches) > 0 {
+          // remove the most recently added match
+          matches = matches[:len(matches)-1]
+        } else if text.re_match(unset_attr_suff, line) {
+          if len(matches) > 0 {
+            matches = matches[:len(matches)-1]
+          }
+        }
+      }
+    }
+  }
+}
+
+if len(matches) == 0 {
+  fmt.println("Attributes are unset properly")
+} else {
+  fmt.println(matches) 
+}