Tweak test and use snippet in utils.

Author: xiongmao86

clippy_lints/src/utils/internal_lints.rs

@@ -1,6 +1,6 @@
 use crate::utils::{
     is_expn_of, match_def_path, match_type, method_calls, paths, span_lint, span_lint_and_help, span_lint_and_sugg,
-    walk_ptrs_ty, snippet_opt, match_path_ast
+    walk_ptrs_ty, snippet as other_snippet, match_path_ast
 };
 use if_chain::if_chain;
 use rustc::hir::map::Map;
@@ -440,10 +440,10 @@ impl  EarlyLintPass for CollapsibleCalls {
 }
 
 struct AndThenArgs {
-    cx: String,
-    lint: String,
-    span: String,
-    msg: String,
+    cx: Cow<'a, str>,
+    lint: Cow<'a, str>,
+    span: Cow<'a, str>,
+    msg: Cow<'a, str>,
 }
 
 fn get_and_then_args(cx: &EarlyContext<'_>, and_then_args: &Vec<P<AstExpr>>) -> AndThenArgs {
@@ -461,10 +461,10 @@ fn get_and_then_args(cx: &EarlyContext<'_>, and_then_args: &Vec<P<AstExpr>>) ->
 }
 
 struct SuggestionArgs {
-    span: String,
-    help: String,
-    sugg: String,
-    applicability: String,
+    span: Cow<'a, str>,
+    help: Cow<'a, str>,
+    sugg: Cow<'a, str>,
+    applicability: Cow<'a, str>,
 }
 
 fn suggestion_args(cx: &EarlyContext<'_>, span_call_args: &Vec<P<AstExpr>>) -> SuggestionArgs {
@@ -506,8 +506,8 @@ fn suggest_span_suggestion(cx: &EarlyContext<'_>, expr: &AstExpr, and_then_args:
 }
 
 struct HelpArgs {
-    span: String,
-    help: String,
+    span: Cow<'a, str>,
+    help: Cow<'a, str>,
 }
 
 fn help_args(cx: &EarlyContext<'_>, span_call_args: &Vec<P<AstExpr>>) -> HelpArgs {
@@ -542,8 +542,8 @@ fn suggest_span_help(cx: &EarlyContext<'_>, expr: &AstExpr, and_then_args: AndTh
 }
 
 struct NoteArgs {
-    span: String,
-    note: String,
+    span: Cow<'a, str>,
+    note: Cow<'a, str>,
 }
 
 fn note_args(cx: &EarlyContext<'_>, span_call_args: &Vec<P<AstExpr>>) -> NoteArgs {
@@ -577,6 +577,6 @@ fn suggest_span_note(cx: &EarlyContext<'_>, expr: &AstExpr, and_then_args: AndTh
     }
 }
 
-fn snippet(cx: &EarlyContext<'_>, span: Span) -> String {
-    snippet_opt(cx, span).expect("should be able to retrive span.")
+fn snippet(cx: &EarlyContext<'_>, span: Span) -> Cow<'a, str> {
+    other_snippet(cx, span, "Should not be")
 }

tests/ui/collapsible_span_lint_calls.rs

@@ -41,11 +41,11 @@ impl EarlyLintPass for Pass {
             db.span_suggestion(expr.span, help_msg, sugg.to_string(), Applicability::MachineApplicable);
         });
         span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |db| {
-            db.span_help(expr.span, help_msg);
-        });
-        span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |db| {
-            db.span_note(expr.span, note_msg);
+            db.span_help(expr.span, help_msg)
         });
+        span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |db|
+            db.span_note(expr.span, note_msg)
+        );
     }
 }