Don’t require fourslash completions tests to specify replacementSpan when it’s zero-length (#42013)

Author: andrewbranch

src/harness/fourslashImpl.ts

@@ -907,11 +907,13 @@ namespace FourSlash {
                 this.raiseError(`Expected completion insert text to be ${expected.insertText}, got ${actual.insertText}`);
             }
             const convertedReplacementSpan = expected.replacementSpan && ts.createTextSpanFromRange(expected.replacementSpan);
-            try {
-                assert.deepEqual(actual.replacementSpan, convertedReplacementSpan);
-            }
-            catch {
-                this.raiseError(`Expected completion replacementSpan to be ${stringify(convertedReplacementSpan)}, got ${stringify(actual.replacementSpan)}`);
+            if (convertedReplacementSpan?.length) {
+                try {
+                    assert.deepEqual(actual.replacementSpan, convertedReplacementSpan);
+                }
+                catch {
+                    this.raiseError(`Expected completion replacementSpan to be ${stringify(convertedReplacementSpan)}, got ${stringify(actual.replacementSpan)}`);
+                }
             }
 
             if (expected.kind !== undefined || expected.kindModifiers !== undefined) {

tests/cases/fourslash/completionsWithGenericStringLiteral.ts

@@ -2,12 +2,9 @@
 // @strict: true
 
 //// declare function get<T, K extends keyof T>(obj: T, key: K): T[K];
-//// get({ hello: 123, world: 456 }, "[|/**/|]");
+//// get({ hello: 123, world: 456 }, "/**/");
 
 verify.completions({
   marker: "",
-  includes: [
-    { name: 'hello', replacementSpan: test.ranges()[0] },
-    { name: 'world', replacementSpan: test.ranges()[0] }
-  ]
+  includes: ["hello", "world"]
 });