Infer void from expr statement usage, not calls

This makes inferences a lot better.

Author: sandersn

src/services/codefixes/inferFromUsage.ts

@@ -504,6 +504,9 @@ namespace ts.codefix {
             }
 
             switch (node.parent.kind) {
+                case SyntaxKind.ExpressionStatement:
+                    addCandidateType(usage, checker.getVoidType());
+                    break;
                 case SyntaxKind.PostfixUnaryExpression:
                     usage.isNumber = true;
                     break;
@@ -871,12 +874,11 @@ namespace ts.codefix {
                 }
 
                 if (usage.calls) {
-                    callSignatures.push(getSignatureFromCalls(usage.calls, checker.getVoidType()));
+                    callSignatures.push(getSignatureFromCalls(usage.calls, checker.getAnyType()));
                 }
 
                 if (usage.constructs) {
-                    // TODO: fallback return should maybe be {}?
-                    constructSignatures.push(getSignatureFromCalls(usage.constructs, checker.getVoidType()));
+                    constructSignatures.push(getSignatureFromCalls(usage.constructs, checker.getAnyType()));
                 }
 
                 if (usage.stringIndex) {

tests/cases/fourslash/codeFixInferFromCallInAssignment.ts

@@ -0,0 +1,9 @@
+/// <reference path='fourslash.ts' />
+
+// @noImplicitAny: true
+//// function inferAny( [| app |] ) {
+////     const result = app.use('hi')
+////     return result
+//// }
+
+verify.rangeAfterCodeFix("app: { use: (arg0: string) => any; }");

tests/cases/fourslash/codeFixInferFromExpressionStatement.ts

@@ -0,0 +1,8 @@
+/// <reference path='fourslash.ts' />
+
+// @noImplicitAny: true
+//// function inferVoid( [| app |] ) {
+////     app.use('hi')
+//// }
+
+verify.rangeAfterCodeFix("app: { use: (arg0: string) => void; }");

tests/cases/fourslash/codeFixInferFromUsageCommentAfterParameter.ts

@@ -16,7 +16,7 @@ verify.codeFix({
     index: 0,
     newFileContent:
 `/**
- * @param {(arg0: any) => void} callback
+ * @param {(arg0: any) => any} callback
  */
 function coll(callback /*, name1, name2, ... */) {
     return callback(this);

tests/cases/fourslash/codeFixInferFromUsageJSXElement.ts

@@ -30,4 +30,4 @@
 //// }
 
 
-verify.rangeAfterCodeFix("props: { isLoading: any; update: (arg0: any) => void; }",/*includeWhiteSpace*/ undefined, /*errorCode*/ undefined, 0);
+verify.rangeAfterCodeFix("props: { isLoading: any; update: (arg0: any) => any; }",/*includeWhiteSpace*/ undefined, /*errorCode*/ undefined, 0);

tests/cases/fourslash/codeFixInferFromUsagePropertyAccess.ts

@@ -12,4 +12,4 @@
 ////    return x.y.z
 ////}
 
-verify.rangeAfterCodeFix("a: { b: { c: any; }; }, m: { n: () => number; }, x: { y: { z: number[]; }; }", /*includeWhiteSpace*/ undefined, /*errorCode*/ undefined, /*index*/0);
+verify.rangeAfterCodeFix("a: { b: { c: void; }; }, m: { n: () => number; }, x: { y: { z: number[]; }; }", /*includeWhiteSpace*/ undefined, /*errorCode*/ undefined, /*index*/0);

tests/cases/fourslash/codeFixInferFromUsagePropertyAccessJS.ts

@@ -21,7 +21,7 @@ verify.codeFix({
     index: 0,
     newFileContent:
 `/**
- * @param {{ b: { c: any; }; }} a
+ * @param {{ b: { c: void; }; }} a
  * @param {{ n: () => number; }} m
  * @param {{ y: { z: number[]; }; }} x
  */