Add UI test where annotated_files count is > 1 #64205

src/test/ui/annotate-snippet/auxiliary/multispan.rs

@@ -0,0 +1,37 @@
+// force-host
+// no-prefer-dynamic
+
+#![crate_type = "proc-macro"]
+#![feature(proc_macro_diagnostic, proc_macro_span, proc_macro_def_site)]
+
+extern crate proc_macro;
+
+use proc_macro::{TokenStream, TokenTree, Span, Diagnostic};
+
+fn parse(input: TokenStream) -> Result<(), Diagnostic> {
+    let mut hi_spans = vec![];
+    for tree in input {
+        if let TokenTree::Ident(ref ident) = tree {
+            if ident.to_string() == "hi" {
+                hi_spans.push(ident.span());
+            }
+        }
+    }
+
+    if !hi_spans.is_empty() {
+        return Err(Span::def_site()
+                       .error("hello to you, too!")
+                       .span_note(hi_spans, "found these 'hi's"));
+    }
+
+    Ok(())
+}
+
+#[proc_macro]
+pub fn hello(input: TokenStream) -> TokenStream {
+    if let Err(diag) = parse(input) {
+        diag.emit();
+    }
+
+    TokenStream::new()
+}

src/test/ui/annotate-snippet/multispan.rs

@@ -0,0 +1,28 @@
+// aux-build:multispan.rs
+// compile-flags: --error-format human-annotate-rs
+
+#![feature(proc_macro_hygiene)]
+
+extern crate multispan;
+
+use multispan::hello;
+
+fn main() {
+    // This one emits no error.
+    hello!();
+
+    // Exactly one 'hi'.
+    hello!(hi); //~ ERROR hello to you, too!
+
+    // Now two, back to back.
+    hello!(hi hi); //~ ERROR hello to you, too!
+
+    // Now three, back to back.
+    hello!(hi hi hi); //~ ERROR hello to you, too!
+
+    // Now several, with spacing.
+    hello!(hi hey hi yo hi beep beep hi hi); //~ ERROR hello to you, too!
+    hello!(hi there, hi how are you? hi... hi.); //~ ERROR hello to you, too!
+    hello!(whoah. hi di hi di ho); //~ ERROR hello to you, too!
+    hello!(hi good hi and good bye); //~ ERROR hello to you, too!
+}

src/test/ui/annotate-snippet/multispan.stderr

@@ -0,0 +1,42 @@
+error: hello to you, too!
+  --> $DIR/multispan.rs:15:5
+   |
+LL |     hello!(hi);
+   |     ^^^^^^^^^^^
+   |
+error: hello to you, too!
+  --> $DIR/multispan.rs:18:5
+   |
+LL |     hello!(hi hi);
+   |     ^^^^^^^^^^^^^^
+   |
+error: hello to you, too!
+  --> $DIR/multispan.rs:21:5
+   |
+LL |     hello!(hi hi hi);
+   |     ^^^^^^^^^^^^^^^^^
+   |
+error: hello to you, too!
+  --> $DIR/multispan.rs:24:5
+   |
+LL |     hello!(hi hey hi yo hi beep beep hi hi);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+error: hello to you, too!
+  --> $DIR/multispan.rs:25:5
+   |
+LL |     hello!(hi there, hi how are you? hi... hi.);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+error: hello to you, too!
+  --> $DIR/multispan.rs:26:5
+   |
+LL |     hello!(whoah. hi di hi di ho);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+error: hello to you, too!
+  --> $DIR/multispan.rs:27:5
+   |
+LL |     hello!(hi good hi and good bye);
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |