feat: add depending .d.ts files as changed when watch is triggered

If a project depends on custom definition files, meaning not the ones in node_modules, then it should consider them changed when webpack triggers a watch-run.
Since webpack doesn't know about definition files, we use the one detected by the languageService which should be more accurate anyway.

Closes TypeStrong#697

Author: Markus Wolf

src/constants.ts

@@ -18,4 +18,5 @@ export const dtsTsTsxRegex = /(\.d)?\.ts(x?)$/i;
 export const dtsTsTsxJsJsxRegex = /((\.d)?\.ts(x?)|js(x?))$/i;
 export const tsTsxJsJsxRegex = /\.tsx?$|\.jsx?$/i;
 export const jsJsx = /\.js(x?)$/i;
-export const jsJsxMap = /\.js(x?)\.map$/i;
+export const jsJsxMap = /\.js(x?)\.map$/i;
+export const nodeModules = /node_modules/i;

src/watch-run.ts

@@ -28,15 +28,28 @@ export function makeWatchRun(
             )
             .forEach(filePath => {
                 lastTimes[filePath] = times[filePath];
-                filePath = path.normalize(filePath);
-                const file = instance.files[filePath];
-                if (file !== undefined) {
-                    file.text = readFile(filePath) || '';
-                    file.version++;
-                    instance.version!++;
-                    instance.modifiedFiles![filePath] = file;
-                }
+                updateFile(instance, filePath);
+            });
+        // On watch update add all known dts files expect the ones in node_modules
+        // (skip @types/* and modules with typings)
+        Object.keys(instance.files)
+            .filter(filePath =>
+                filePath.match(constants.dtsDtsxRegex) && !filePath.match(constants.nodeModules)
+            )
+            .forEach(filePath => {
+                updateFile(instance, filePath);
             });
         cb();
     };
 }
+
+function updateFile(instance: TSInstance, filePath: string) {
+    filePath = path.normalize(filePath);
+    const file = instance.files[filePath];
+    if (file !== undefined) {
+        file.text = readFile(filePath) || '';
+        file.version++;
+        instance.version!++;
+        instance.modifiedFiles![filePath] = file;
+    }
+}