fix(transformer): apply null and warning when property type cannot be identified

Author: Pmyl

src/transformer/descriptor/property/propertySignature.ts

@@ -1,6 +1,8 @@
 import * as ts from 'typescript';
 import { Scope } from '../../scope/scope';
 import { GetDescriptor } from '../descriptor';
+import { TransformerLogger } from '../../logger/transformerLogger';
+import { GetNullDescriptor } from '../null/null';
 import { PropertySignatureCache } from './cache';
 
 type PropertyNode = ts.PropertySignature | ts.PropertyDeclaration;
@@ -16,9 +18,8 @@ export function GetPropertyDescriptor(
   }
 
   if (!node.initializer) {
-    throw new Error(
-      `The transformer couldn't determine a property value for \`${node.getText()}' without a specified type nor an initializer value.`
-    );
+    TransformerLogger().typeOfPropertyNotFound(node);
+    return GetNullDescriptor();
   }
 
   return GetDescriptor(node.initializer, scope);

src/transformer/logger/transformerLogger.ts

@@ -14,6 +14,8 @@ export interface TransformerLogger {
 
   typeOfFunctionCallNotFound(node: string): void;
 
+  typeOfPropertyNotFound(node: ts.Node): void;
+
   indexedAccessTypeFailed(
     propertyName: string,
     nodeText: string,
@@ -83,6 +85,17 @@ export function TransformerLogger(): TransformerLogger {
         `Cannot find type of function call: ${node} - it will convert to null`
       );
     },
+    typeOfPropertyNotFound(node: ts.Node): void {
+      const createMockNode: ts.Node = GetCurrentCreateMock();
+
+      const createMockFileUrl: string = getNodeFileUrl(createMockNode);
+      const currentNodeFileUrl: string = getNodeFileUrl(node);
+
+      logger.warning(
+        `The transformer could not determine a property value for ${node.getText()} without a specified type nor an initializer value - it will convert to null
+${warningPositionLog(createMockFileUrl, currentNodeFileUrl)}`
+      );
+    },
     indexedAccessTypeFailed(
       propertyName: string,
       nodeText: string,

test/logs/untypedProperty/untypedProperty.warning.test.ts

@@ -0,0 +1,26 @@
+import { createMock } from 'ts-auto-mock';
+import { getLogsByCreateMockFileName, UnsupportedTypeLog } from '../utils/log';
+import { InterfacePropFallbackAny } from './untypedProperty.warning.type';
+
+describe('Untyped property Warning', () => {
+  it('should log a warning and apply null to the property', async () => {
+    const logs: UnsupportedTypeLog[] = await getLogsByCreateMockFileName(
+      'untypedProperty.warning.test.ts'
+    );
+
+    createMock<InterfacePropFallbackAny>();
+    expect(logs.length).toBe(1);
+
+    expect(logs[0].header).toContain(
+      'WARNING: Transformer - The transformer could not determine' +
+        ' a property value for prop; ' +
+        'without a specified type nor an initializer value - it will convert to null'
+    );
+    expect(logs[0].created).toMatch(
+      /created file:\/\/.*untypedProperty\.warning\.test\.ts:[0-9]*:[0-9]*/
+    );
+    expect(logs[0].usedBy).toMatch(
+      /used by file:\/\/.*untypedProperty\.warning\.type\.ts:[0-9]*:[0-9]*/
+    );
+  });
+});

test/logs/untypedProperty/untypedProperty.warning.type.ts

@@ -0,0 +1,4 @@
+export interface InterfacePropFallbackAny {
+  // eslint-disable-next-line @typescript-eslint/typedef
+  prop;
+}