Testcases for eval 'this' binding (C and ES)

tests/api/test-eval-this-binding.c

@@ -0,0 +1,52 @@
+/*
+ *  Test 'this' binding for eval code: https://github.com/svaarala/duktape/issues/164
+ */
+
+/*===
+*** test_1 (duk_safe_call)
+non-strict eval from C
+not an error in non-strict mode
+object
+object
+strict eval from C
+ReferenceError
+object
+object
+final top: 0
+==> rc=0, result='undefined'
+===*/
+
+static duk_ret_t test_1(duk_context *ctx) {
+	/* For non-strict eval code the 'this' binding was effectively
+	 * the global object even before fixing GH-164: an undefined
+	 * 'this' binding gets promoted to the global object by the
+	 * usual Ecmascript call handling semantics.
+	 */
+	duk_eval_string(ctx,
+		"print('non-strict eval from C');\n"
+		"try { dummy1 = 1; print('not an error in non-strict mode'); } catch (e) { print(e.name); }\n"
+		"print(typeof this);\n"
+		"print(typeof (this || {}).Math);\n"
+	);
+	duk_pop(ctx);
+
+	/* For strict eval code the 'this' binding was undefined when
+	 * eval was being done from C code (but was the global object
+	 * when done from Ecmascript code).  With GH-164 fixed the
+	 * 'this' binding is global object for strict eval code too.
+	 */
+
+	duk_eval_string_noresult(ctx,
+		"'use strict'\n"
+		"print('strict eval from C');\n"
+		"try { dummy2 = 1; print('error in strict mode'); } catch (e) { print(e.name); }\n"
+		"print(typeof this);\n"
+		"print(typeof (this || {}).Math);\n"
+	);
+	printf("final top: %ld\n", (long) duk_get_top(ctx));
+	return 0;
+}
+
+void test(duk_context *ctx) {
+	TEST_SAFE_CALL(test_1);
+}

tests/ecmascript/test-dev-eval-this-binding.js

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+/*
+ *  Demonstrate 'this' binding behavior for "direct calls to eval" made
+ *  from Ecmascript code.  The behavior for both strict and non-strict is
+ *  the same: the 'this' binding is inherited from the calling context,
+ *  see E5.1 Section 10.4.2:
+ *
+ *    - Step 2 will match (direct call) and establish a 'this' binding
+ *      in step 2.a, independent of target code strictness.
+ *
+ *    - Step 3 will match for strict code only and will update the lexical
+ *      environment, but the 'this' binding is not affected.
+ *
+ *  The C API eval behavior (duk_(p)eval_*) was different prior to Duktape 1.3:
+ *  eval code 'this' binding was the global object for non-strict eval code,
+ *  but undefined for strict eval code.  This was fixed as part of GH-164:
+ *
+ *      https://github.com/svaarala/duktape/issues/164
+ */
+
+/*===
+non-strict eval code
+not an error in non-strict code
+object
+object
+strict eval code
+ReferenceError
+object
+object
+===*/
+
+function test() {
+    eval("print('non-strict eval code');\n" +
+         "try { dummy1 = 1; print('not an error in non-strict code'); } catch (e) { print(e.name); }\n" +
+         "print(typeof this);\n" +
+         "print(typeof (this || {}).Math);\n");
+
+    eval("'use strict';\n" +
+         "print('strict eval code');\n" +
+         "try { dummy2 = 1; print('error in non-strict code'); } catch (e) { print(e.name); }\n" +
+         "print(typeof this);\n" +
+         "print(typeof (this || {}).Math);\n");
+}
+
+try {
+    test();
+} catch (e) {
+    print(e.stack || e);
+}