move sanitizers from sharedxss::sanitizer to EscapeFunction::Range, added proper inline tests

Author: am0o0

go/ql/lib/semmle/go/frameworks/Fasthttp.qll

@@ -148,15 +148,20 @@ module Fasthttp {
     /**
      * A function that can be used as a sanitizer for XSS.
      */
-    class HtmlQuoteSanitizer extends SharedXss::Sanitizer {
+    class HtmlQuoteSanitizer extends EscapeFunction::Range {
+      boolean isHTMLEscape;
+
       HtmlQuoteSanitizer() {
-        exists(DataFlow::CallNode c |
-          c.getTarget()
-              .hasQualifiedName(packagePath(),
-                ["AppendHTMLEscape", "AppendHTMLEscapeBytes", "AppendQuotedArg"])
-        |
-          this = c.getArgument(1)
-        )
+        this.hasQualifiedName(packagePath(), ["AppendHTMLEscape", "AppendHTMLEscapeBytes"]) and
+        isHTMLEscape = true
+        or
+        this.hasQualifiedName(packagePath(), "AppendQuotedArg") and isHTMLEscape = false
+      }
+
+      override string kind() {
+        isHTMLEscape = true and result = "html"
+        or
+        isHTMLEscape = false and result = "url"
       }
     }
 

go/ql/test/library-tests/semmle/go/frameworks/Fasthttp/EscapeFunction.expected

@@ -0,0 +1,2 @@
+testFailures
+failures

go/ql/test/library-tests/semmle/go/frameworks/Fasthttp/EscapeFunction.ql

@@ -0,0 +1,18 @@
+import go
+import TestUtilities.InlineExpectationsTest
+
+module FasthttpTest implements TestSig {
+  string getARelevantTag() { result = "Sanitizer" }
+
+  predicate hasActualResult(Location location, string element, string tag, string value) {
+    exists(EscapeFunction ef, DataFlow::CallNode cn | cn = ef.getACall() |
+      cn.hasLocationInfo(location.getFile().getAbsolutePath(), location.getStartLine(),
+        location.getStartColumn(), location.getEndLine(), location.getEndColumn()) and
+      element = cn.getArgument(1).toString() and
+      value = cn.getArgument(1).toString() and
+      tag = "Sanitizer"
+    )
+  }
+}
+
+import MakeTest<FasthttpTest>