Revert "Move the warning message outside of the parser function"

This reverts commit 547db22.

Author: j-f1

parser.js

@@ -16,21 +16,8 @@ const SUPPORTED_TYPESCRIPT_VERSIONS = require("./package.json").devDependencies.
 const ACTIVE_TYPESCRIPT_VERSION = ts.version;
 const isRunningSupportedTypeScriptVersion = semver.satisfies(ACTIVE_TYPESCRIPT_VERSION, SUPPORTED_TYPESCRIPT_VERSIONS);
 
-if (!isRunningSupportedTypeScriptVersion) {
-    const border = "=============";
-    const versionWarning = [
-        border,
-        "WARNING: You are currently running a version of TypeScript which is not officially supported by typescript-eslint-parser.",
-        "You may find that it works just fine, or you may not.",
-        `SUPPORTED TYPESCRIPT VERSIONS: ${SUPPORTED_TYPESCRIPT_VERSIONS}`,
-        `YOUR TYPESCRIPT VERSION: ${ACTIVE_TYPESCRIPT_VERSION}`,
-        "Please only submit bug reports when using the officially supported version.",
-        border
-    ];
-    console.log(versionWarning.join("\n\n")); // eslint-disable-line no-console
-}
-
 let extra;
+let warnedAboutTSVersion = false;
 
 /**
  * Resets the extra config object
@@ -117,6 +104,21 @@ function parse(code, options) {
 
     }
 
+    if (!isRunningSupportedTypeScriptVersion && !warnedAboutTSVersion) {
+        const border = "=============";
+        const versionWarning = [
+            border,
+            "WARNING: You are currently running a version of TypeScript which is not officially supported by typescript-eslint-parser.",
+            "You may find that it works just fine, or you may not.",
+            `SUPPORTED TYPESCRIPT VERSIONS: ${SUPPORTED_TYPESCRIPT_VERSIONS}`,
+            `YOUR TYPESCRIPT VERSION: ${ACTIVE_TYPESCRIPT_VERSION}`,
+            "Please only submit bug reports when using the officially supported version.",
+            border
+        ];
+        extra.log(versionWarning.join("\n\n"));
+        warnedAboutTSVersion = true;
+    }
+
     // Even if jsx option is set in typescript compiler, filename still has to
     // contain .tsx file extension
     const FILENAME = (extra.ecmaFeatures.jsx) ? "eslint.tsx" : "eslint.ts";