Rephrase error message to be 100% technically correct (#50471)

Author: RyanCavanaugh

src/compiler/checker.ts

@@ -34582,26 +34582,19 @@ namespace ts {
             }
 
             function tryGiveBetterPrimaryError(errNode: Node, maybeMissingAwait: boolean, leftStr: string, rightStr: string) {
-                let typeName: string | undefined;
                 switch (operatorToken.kind) {
                     case SyntaxKind.EqualsEqualsEqualsToken:
                     case SyntaxKind.EqualsEqualsToken:
-                        typeName = "false";
-                        break;
                     case SyntaxKind.ExclamationEqualsEqualsToken:
                     case SyntaxKind.ExclamationEqualsToken:
-                        typeName = "true";
-                }
-
-                if (typeName) {
-                    return errorAndMaybeSuggestAwait(
-                        errNode,
-                        maybeMissingAwait,
-                        Diagnostics.This_condition_will_always_return_0_since_the_types_1_and_2_have_no_overlap,
-                        typeName, leftStr, rightStr);
+                        return errorAndMaybeSuggestAwait(
+                            errNode,
+                            maybeMissingAwait,
+                            Diagnostics.This_comparison_appears_to_be_unintentional_because_the_types_0_and_1_have_no_overlap,
+                            leftStr, rightStr);
+                    default:
+                        return undefined;
                 }
-
-                return undefined;
             }
         }
 

src/compiler/diagnosticMessages.json

@@ -1864,7 +1864,7 @@
         "category": "Error",
         "code": 2366
     },
-    "This condition will always return '{0}' since the types '{1}' and '{2}' have no overlap.": {
+    "This comparison appears to be unintentional because the types '{0}' and '{1}' have no overlap.": {
         "category": "Error",
         "code": 2367
     },

src/services/codefixes/addMissingAwait.ts

@@ -13,7 +13,7 @@ namespace ts.codefix {
         Diagnostics.The_right_hand_side_of_an_arithmetic_operation_must_be_of_type_any_number_bigint_or_an_enum_type.code,
         Diagnostics.Operator_0_cannot_be_applied_to_type_1.code,
         Diagnostics.Operator_0_cannot_be_applied_to_types_1_and_2.code,
-        Diagnostics.This_condition_will_always_return_0_since_the_types_1_and_2_have_no_overlap.code,
+        Diagnostics.This_comparison_appears_to_be_unintentional_because_the_types_0_and_1_have_no_overlap.code,
         Diagnostics.This_condition_will_always_return_true_since_this_0_is_always_defined.code,
         Diagnostics.Type_0_is_not_an_array_type.code,
         Diagnostics.Type_0_is_not_an_array_type_or_a_string_type.code,

src/testRunner/unittests/tsserver/skipLibCheck.ts

@@ -167,7 +167,7 @@ namespace ts.projectSystem {
             );
             const errorResult = session.executeCommand(getErrRequest).response as protocol.Diagnostic[];
             assert.isTrue(errorResult.length === 1);
-            assert.equal(errorResult[0].code, Diagnostics.This_condition_will_always_return_0_since_the_types_1_and_2_have_no_overlap.code);
+            assert.equal(errorResult[0].code, Diagnostics.This_comparison_appears_to_be_unintentional_because_the_types_0_and_1_have_no_overlap.code);
         });
 
         it("should report semantic errors for configured js project with '// @ts-check' and skipLibCheck=true", () => {
@@ -194,7 +194,7 @@ namespace ts.projectSystem {
             );
             const errorResult = session.executeCommand(getErrRequest).response as protocol.Diagnostic[];
             assert.isTrue(errorResult.length === 1);
-            assert.equal(errorResult[0].code, Diagnostics.This_condition_will_always_return_0_since_the_types_1_and_2_have_no_overlap.code);
+            assert.equal(errorResult[0].code, Diagnostics.This_comparison_appears_to_be_unintentional_because_the_types_0_and_1_have_no_overlap.code);
         });
 
         it("should report semantic errors for configured js project with checkJs=true and skipLibCheck=true", () => {
@@ -223,7 +223,7 @@ namespace ts.projectSystem {
             );
             const errorResult = session.executeCommand(getErrRequest).response as protocol.Diagnostic[];
             assert.isTrue(errorResult.length === 1);
-            assert.equal(errorResult[0].code, Diagnostics.This_condition_will_always_return_0_since_the_types_1_and_2_have_no_overlap.code);
+            assert.equal(errorResult[0].code, Diagnostics.This_comparison_appears_to_be_unintentional_because_the_types_0_and_1_have_no_overlap.code);
         });
     });
 }

tests/baselines/reference/capturedLetConstInLoop5.errors.txt

@@ -1,5 +1,5 @@
-tests/cases/compiler/capturedLetConstInLoop5.ts(174,13): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop5.ts(229,13): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop5.ts(174,13): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop5.ts(229,13): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
 
 
 ==== tests/cases/compiler/capturedLetConstInLoop5.ts (2 errors) ====
@@ -178,7 +178,7 @@ tests/cases/compiler/capturedLetConstInLoop5.ts(229,13): error TS2367: This cond
             (() => x + v);
             if (x == 1) {
                 ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
                 return;
             }
         }
@@ -235,7 +235,7 @@ tests/cases/compiler/capturedLetConstInLoop5.ts(229,13): error TS2367: This cond
             (() => x + y + v);
             if (x == 1) {
                 ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
                 return;
             }
         }

tests/baselines/reference/capturedLetConstInLoop5_ES6.errors.txt

@@ -1,5 +1,5 @@
-tests/cases/compiler/capturedLetConstInLoop5_ES6.ts(174,13): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop5_ES6.ts(229,13): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop5_ES6.ts(174,13): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop5_ES6.ts(229,13): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
 
 
 ==== tests/cases/compiler/capturedLetConstInLoop5_ES6.ts (2 errors) ====
@@ -178,7 +178,7 @@ tests/cases/compiler/capturedLetConstInLoop5_ES6.ts(229,13): error TS2367: This
             (() => x + v);
             if (x == 1) {
                 ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
                 return;
             }
         }
@@ -235,7 +235,7 @@ tests/cases/compiler/capturedLetConstInLoop5_ES6.ts(229,13): error TS2367: This
             (() => x + y + v);
             if (x == 1) {
                 ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
                 return;
             }
         }

tests/baselines/reference/capturedLetConstInLoop6.errors.txt

@@ -1,7 +1,7 @@
-tests/cases/compiler/capturedLetConstInLoop6.ts(147,9): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop6.ts(150,9): error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop6.ts(194,9): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop6.ts(197,9): error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop6.ts(147,9): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop6.ts(150,9): error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop6.ts(194,9): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop6.ts(197,9): error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
 
 
 ==== tests/cases/compiler/capturedLetConstInLoop6.ts (4 errors) ====
@@ -153,12 +153,12 @@ tests/cases/compiler/capturedLetConstInLoop6.ts(197,9): error TS2367: This condi
         (() => x);
         if (x == 1) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
             break;
         }
         if (x == 2) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
             continue;
         }
     }
@@ -204,12 +204,12 @@ tests/cases/compiler/capturedLetConstInLoop6.ts(197,9): error TS2367: This condi
         (() => x + y);
         if (x == 1) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
             break;
         }
         if (x == 2) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
             continue;
         }
     }

tests/baselines/reference/capturedLetConstInLoop6_ES6.errors.txt

@@ -1,7 +1,7 @@
-tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(147,9): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(150,9): error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(194,9): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(197,9): error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(147,9): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(150,9): error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(194,9): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(197,9): error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
 
 
 ==== tests/cases/compiler/capturedLetConstInLoop6_ES6.ts (4 errors) ====
@@ -153,12 +153,12 @@ tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(197,9): error TS2367: This c
         (() => x);
         if (x == 1) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
             break;
         }
         if (x == 2) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
             continue;
         }
     }
@@ -204,12 +204,12 @@ tests/cases/compiler/capturedLetConstInLoop6_ES6.ts(197,9): error TS2367: This c
         (() => x + y);
         if (x == 1) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
             break;
         }
         if (x == 2) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
             continue;
         }
     }

tests/baselines/reference/capturedLetConstInLoop7.errors.txt

@@ -1,11 +1,11 @@
-tests/cases/compiler/capturedLetConstInLoop7.ts(230,9): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop7.ts(233,9): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop7.ts(236,9): error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop7.ts(239,9): error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop7.ts(305,9): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop7.ts(308,9): error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop7.ts(311,9): error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
-tests/cases/compiler/capturedLetConstInLoop7.ts(314,9): error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop7.ts(230,9): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop7.ts(233,9): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop7.ts(236,9): error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop7.ts(239,9): error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop7.ts(305,9): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop7.ts(308,9): error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop7.ts(311,9): error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
+tests/cases/compiler/capturedLetConstInLoop7.ts(314,9): error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
 
 
 ==== tests/cases/compiler/capturedLetConstInLoop7.ts (8 errors) ====
@@ -240,22 +240,22 @@ tests/cases/compiler/capturedLetConstInLoop7.ts(314,9): error TS2367: This condi
         (() => x);
         if (x == 1) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
             break;
         }
         if (x == 1) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
             break l1_c;
         }
         if (x == 2) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
             continue;
         }
         if (x == 2) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
             continue l1_c;
         }
     }
@@ -323,22 +323,22 @@ tests/cases/compiler/capturedLetConstInLoop7.ts(314,9): error TS2367: This condi
         (() => x + y);
         if (x == 1) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
             break;
         }
         if (x == 1) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '1' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '1' have no overlap.
             break l5_c;
         }
         if (x == 2) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
             continue;
         }
         if (x == 2) {
             ~~~~~~
-!!! error TS2367: This condition will always return 'false' since the types '0' and '2' have no overlap.
+!!! error TS2367: This comparison appears to be unintentional because the types '0' and '2' have no overlap.
             continue l5_c;
         }
     }