Use issue expectation helpers in Performance::CompactAfterMap rule spec

spec/ameba/rule/performance/compact_after_map_spec.cr

@@ -5,39 +5,35 @@ module Ameba::Rule::Performance
 
   describe CompactAfterMap do
     it "passes if there is no potential performance improvements" do
-      source = Source.new %(
+      expect_no_issues subject, <<-CRYSTAL
         (1..3).compact_map(&.itself)
-      )
+        CRYSTAL
-      subject.catch(source).should be_valid
     end
 
     it "passes if there is map followed by a bang call" do
-      source = Source.new %(
+      expect_no_issues subject, <<-CRYSTAL
         (1..3).map(&.itself).compact!
-      )
+        CRYSTAL
-      subject.catch(source).should be_valid
     end
 
     it "reports if there is map followed by compact call" do
-      source = Source.new %(
+      expect_issue subject, <<-CRYSTAL
         (1..3).map(&.itself).compact
-      )
+             # ^^^^^^^^^^^^^^^^^^^^^^ error: Use `compact_map {...}` instead of `map {...}.compact`
-      subject.catch(source).should_not be_valid
+        CRYSTAL
     end
 
     it "does not report if source is a spec" do
-      source = Source.new %(
+      expect_no_issues subject, path: "source_spec.cr", code: <<-CRYSTAL
         (1..3).map(&.itself).compact
-      ), "source_spec.cr"
+        CRYSTAL
-      subject.catch(source).should be_valid
     end
 
     context "macro" do
       it "doesn't report in macro scope" do
-        source = Source.new %(
+        expect_no_issues subject, <<-CRYSTAL
           {{ [1, 2, 3].map(&.to_s).compact }}
-        )
+          CRYSTAL
-        subject.catch(source).should be_valid
       end
     end