fix(*): Add severity, start and end column numbers for diagnostics, change warning to message

src/types/Diagnostic.ts

@@ -1,8 +1,12 @@
+import { Severity } from './Severity'
+
 /**
  * A diagnostic is produced by the execution of a lint rule against a file or line of text.
  */
 export interface Diagnostic {
   lineNumber: number
-  columnNumber: number
-  warning: string
+  startColumnNumber: number
+  endColumnNumber: number
+  message: string
+  severity: Severity
 }

src/types/LintRule.ts

@@ -2,14 +2,14 @@ import { Diagnostic } from './Diagnostic'
 import { LintRuleType } from './LintRuleType'
 
 /**
- * A lint rule is defined by a type, name, description, warning text and a test function.
+ * A lint rule is defined by a type, name, description, message text and a test function.
  * The test function produces a set of diagnostics when executed.
  */
 export interface LintRule {
   type: LintRuleType
   name: string
   description: string
-  warning: string
+  message: string
   test: (value: string, lineNumber: number) => Diagnostic[]
 }
 

src/types/Severity.ts

@@ -0,0 +1,8 @@
+/**
+ * Severity indicates the seriousness of a given violation.
+ */
+export enum Severity {
+  Info,
+  Warning,
+  Error
+}