Improve some diagnostic messages

Change-Id: Ic351c2addff76dea8fe49c7e2ce68b46043f0814
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/177480
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>

Author: bwilkerson

pkg/analyzer/lib/src/error/codes.dart

@@ -9204,7 +9204,7 @@ class CompileTimeErrorCode extends AnalyzerErrorCode {
   static const CompileTimeErrorCode RETURN_OF_INVALID_TYPE_FROM_CONSTRUCTOR =
       CompileTimeErrorCode(
     'RETURN_OF_INVALID_TYPE',
-    "A value of type '{0}' can't be returned from constructor '{2}' "
+    "A value of type '{0}' can't be returned from the constructor '{2}' "
         "because it has a return type of '{1}'.",
     hasPublishedDocs: true,
     uniqueName: 'RETURN_OF_INVALID_TYPE_FROM_CONSTRUCTOR',
@@ -9247,7 +9247,7 @@ class CompileTimeErrorCode extends AnalyzerErrorCode {
   static const CompileTimeErrorCode RETURN_OF_INVALID_TYPE_FROM_FUNCTION =
       CompileTimeErrorCode(
     'RETURN_OF_INVALID_TYPE',
-    "A value of type '{0}' can't be returned from function '{2}' because "
+    "A value of type '{0}' can't be returned from the function '{2}' because "
         "it has a return type of '{1}'.",
     hasPublishedDocs: true,
     uniqueName: 'RETURN_OF_INVALID_TYPE_FROM_FUNCTION',
@@ -9262,7 +9262,7 @@ class CompileTimeErrorCode extends AnalyzerErrorCode {
   static const CompileTimeErrorCode RETURN_OF_INVALID_TYPE_FROM_METHOD =
       CompileTimeErrorCode(
     'RETURN_OF_INVALID_TYPE',
-    "A value of type '{0}' can't be returned from method '{2}' because "
+    "A value of type '{0}' can't be returned from the method '{2}' because "
         "it has a return type of '{1}'.",
     hasPublishedDocs: true,
     uniqueName: 'RETURN_OF_INVALID_TYPE_FROM_METHOD',

pkg/analyzer/tool/diagnostics/diagnostics.md

@@ -7475,13 +7475,13 @@ class C {
 
 ### return_of_invalid_type
 
-_A value of type '{0}' can't be returned from constructor '{2}' because it has a
-return type of '{1}'._
+_A value of type '{0}' can't be returned from the constructor '{2}' because it
+has a return type of '{1}'._
 
-_A value of type '{0}' can't be returned from function '{2}' because it has a
-return type of '{1}'._
+_A value of type '{0}' can't be returned from the function '{2}' because it has
+a return type of '{1}'._
 
-_A value of type '{0}' can't be returned from method '{2}' because it has a
+_A value of type '{0}' can't be returned from the method '{2}' because it has a
 return type of '{1}'._
 
 #### Description

pkg/nnbd_migration/test/migration_cli_test.dart

@@ -2078,8 +2078,8 @@ environment:
     expect(errorOutput, contains('1 analysis issue found:'));
     expect(
         errorOutput,
-        contains("A value of type 'Null' can't be returned from function 'f' "
-            "because it has a return type of 'int'"));
+        contains("A value of type 'Null' can't be returned from the function "
+            "'f' because it has a return type of 'int'"));
     expect(errorOutput, contains('Set the lower SDK constraint'));
   }