Logical "||" operator.

test/and.wren

@@ -18,3 +18,9 @@ io.write(true) && // expect: true
 // Swallow a trailing newline.
 io.write(true &&
     true) // expect: true
+
+// Only false is falsy.
+io.write(0 && true) // expect: true
+io.write(null && true) // expect: true
+io.write("" && true) // expect: true
+io.write(false && true) // expect: false

test/if.wren

@@ -44,3 +44,8 @@ if (true) class Foo {} // no error
 // Definition in else arm.
 if (false) null else var a = io.write("ok") // expect: ok
 if (true) null else class Foo {} // no error
+
+// Only false is falsy.
+if (0) io.write(0) // expect: 0
+if (null) io.write(null) // expect: null
+if ("") io.write("empty") // expect: empty

test/or.wren

@@ -0,0 +1,26 @@
+// Note: These tests implicitly depend on ints being truthy.
+//       Also rely on io.write() returning its argument.
+
+// Return the first true argument.
+io.write(1 || true) // expect: 1
+io.write(false || 1) // expect: 1
+io.write(false || false || true) // expect: true
+
+// Return the last argument if all are false.
+io.write(false || false) // expect: false
+io.write(false || false || false) // expect: false
+
+// Short-circuit at the first true argument.
+io.write(false) || // expect: false
+    io.write(true) || // expect: true
+    io.write(true) // should not print
+
+// Swallow a trailing newline.
+io.write(true ||
+    true) // expect: true
+
+// Only false is falsy.
+io.write(0 || true) // expect: 0
+io.write(null || true) // expect: null
+io.write(("" || true) == "") // expect: true
+io.write(false || true) // expect: true