test: add failing tests for multi-line token JSON serialization bug

These tests demonstrate that scanSync throws 'Bad control character in
string literal' when scanning SQL with multi-line tokens (dollar-quoted
function bodies, tabs, multi-line C-style comments).

The root cause is that build_scan_json() in wasm_wrapper.c only escapes
'"' and '\\' in token text, but not '\n', '\r', '\t'. When token text
contains literal newlines, the JSON output has unescaped control chars
that break JSON.parse.

These tests are expected to FAIL on this branch (no fix applied).
See PR #147 for the fix.

Author: pyramation

full/test/scan.test.js

@@ -225,5 +225,49 @@ describe("Query Scanning", () => {
       assert.equal(typeof result1.version, "number");
       assert.ok(result1.version > 0);
     });
+
+    it("should handle multi-line dollar-quoted strings without JSON errors", () => {
+      // This tests that the JSON serialization properly escapes control
+      // characters (newlines, tabs) inside token text fields.
+      // Without a fix, scanSync throws: "Bad control character in string literal"
+      const sql = `CREATE FUNCTION test() RETURNS void AS $$
+BEGIN
+  RAISE NOTICE 'hello';
+END;
+$$ LANGUAGE plpgsql`;
+      
+      const result = query.scanSync(sql);
+      assert.equal(typeof result, "object");
+      assert.ok(Array.isArray(result.tokens));
+      assert.ok(result.tokens.length > 0);
+      
+      // Find the dollar-quoted string token
+      const dollarToken = result.tokens.find(t => t.text.includes('BEGIN'));
+      assert.ok(dollarToken, "should have a token containing the function body");
+      assert.ok(dollarToken.text.includes('\n'), "token text should contain newlines");
+    });
+
+    it("should handle multi-line tokens with tabs", () => {
+      const sql = "SELECT $$line1\n\tindented\nline3$$";
+      
+      const result = query.scanSync(sql);
+      assert.equal(typeof result, "object");
+      assert.ok(Array.isArray(result.tokens));
+      
+      const dollarToken = result.tokens.find(t => t.text.includes('indented'));
+      assert.ok(dollarToken, "should have a token containing the tabbed content");
+    });
+
+    it("should handle multi-line SQL comments", () => {
+      const sql = "SELECT 1; /* multi\nline\ncomment */ SELECT 2";
+      
+      const result = query.scanSync(sql);
+      assert.equal(typeof result, "object");
+      assert.ok(Array.isArray(result.tokens));
+      
+      const commentToken = result.tokens.find(t => t.tokenName === "C_COMMENT");
+      assert.ok(commentToken, "should have a C_COMMENT token");
+      assert.ok(commentToken.text.includes('\n'), "comment text should contain newlines");
+    });
   });
-});
+});