Add regression test for span 1-indexed check

tests/rustdoc-json/impls/auto.rs

@@ -15,8 +15,8 @@ impl Foo {
 }
 
 // Testing spans, so all tests below code
-//@ is "$.index[?(@.docs=='has span')].span.begin" "[13, 0]"
-//@ is "$.index[?(@.docs=='has span')].span.end" "[15, 1]"
+//@ is "$.index[?(@.docs=='has span')].span.begin" "[13, 1]"
+//@ is "$.index[?(@.docs=='has span')].span.end" "[15, 2]"
 // FIXME: this doesn't work due to https://github.com/freestrings/jsonpath/issues/91
 // is "$.index[?(@.inner.impl.is_synthetic==true)].span" null
 pub struct Foo;

tests/rustdoc-json/span.rs

@@ -0,0 +1,4 @@
+pub mod bar {}
+// This test ensures that spans are 1-indexed.
+//@ is "$.index[?(@.name=='span')].span.begin" "[1, 1]"
+//@ is "$.index[?(@.name=='bar')].span.begin" "[1, 1]"