Fix StdioOverrideFunction Type export

This was a case of bad management of the types in play and their
exposure outside the package. The fix that works for both package
maintenance, and external users is to ensure that the type is available
and copied into the final npm package. Finally this would have been
caught with a test, which has now been added.

- Fix #40
- Add dedicated type file for StdioOverrideFunction
- Change type file paths to be relative
- Move all type files to the `src` folder to make things easier
- Add Makefile rules to copy over `.d.ts` files so they are in the
  package

Makefile

@@ -16,7 +16,7 @@ dist/test/integration/foobar_magic dist/test/integration/png_magic dist/test/int
 
 package: dist/index.js dist/libmagic.LICENSE
 
-dist/index.js: $(ts_files) dist/libmagic-wrapper.js
+dist/index.js: $(ts_files) dist/libmagic-wrapper.js dist/LibmagicModule.d.ts dist/StdioOverrideFunction.d.ts
 	npx tsc -d
 
 dist/libmagic-wrapper.js: src/libmagic-wrapper.c dist/magic.mgc dist/libmagic.so dist/libmagic-wrapper.d.ts
@@ -31,8 +31,14 @@ dist/libmagic-wrapper.js: src/libmagic-wrapper.c dist/magic.mgc dist/libmagic.so
 	-o dist/libmagic-wrapper.js \
 	src/libmagic-wrapper.c
 
-dist/libmagic-wrapper.d.ts: types/libmagic-wrapper.d.ts
-	cp types/libmagic-wrapper.d.ts dist/libmagic-wrapper.d.ts
+dist/libmagic-wrapper.d.ts: src/libmagic-wrapper.d.ts
+	cp src/libmagic-wrapper.d.ts dist/libmagic-wrapper.d.ts
+
+dist/LibmagicModule.d.ts: src/LibmagicModule.d.ts
+	cp src/LibmagicModule.d.ts dist/LibmagicModule.d.ts
+
+dist/StdioOverrideFunction.d.ts: src/StdioOverrideFunction.d.ts
+	cp src/StdioOverrideFunction.d.ts dist/StdioOverrideFunction.d.ts
 
 dist/libmagic.LICENSE: vendor/file/COPYING
 	cp vendor/file/COPYING dist/libmagic.LICENSE

dist/.npmignore

@@ -2,3 +2,5 @@
 !index.*
 !*LICENSE
 !libmagic-wrapper.*
+!LibmagicModule.d.ts
+!StdioOverrideFunction.d.ts

types/LibmagicModule.d.ts → src/LibmagicModule.d.ts

@@ -1,11 +1,10 @@
-type StdioOverrideFunction = (
-  stdioName: "stdout" | "stderr",
-  text: string,
-) => void;
+import StdioOverrideFunction from "./StdioOverrideFunction";
 
 interface LibmagicModule extends EmscriptenModule {
   FS: typeof FS;
   ccall: typeof ccall;
   cwrap: typeof cwrap;
   printOverride: StdioOverrideFunction;
 }
+
+export default LibmagicModule;

src/StdioOverrideFunction.d.ts

@@ -0,0 +1,6 @@
+type StdioOverrideFunction = (
+  stdioName: "stdout" | "stderr",
+  text: string,
+) => void;
+
+export default StdioOverrideFunction;

src/index.ts

@@ -1,4 +1,7 @@
-import libmagicFactory from "../dist/libmagic-wrapper";
+import libmagicFactory from "./libmagic-wrapper";
+import LibmagicModule from "./LibmagicModule";
+import StdioOverrideFunction from "./StdioOverrideFunction";
+export { default as StdioOverrideFunction } from "./StdioOverrideFunction";
 
 declare function wrappedDetect(bufPointer: number, bufLength: number): string;
 

types/libmagic-wrapper.d.ts → src/libmagic-wrapper.d.ts

@@ -1,2 +1,4 @@
+import LibmagicModule from "./LibmagicModule";
+
 declare const factory: EmscriptenModuleFactory<LibmagicModule>;
 export default factory;

src/test/integration/index.ts

@@ -2,7 +2,7 @@ import * as fs from "fs";
 import * as path from "path";
 import { glob } from "glob";
 import { cases } from "./data";
-import { WASMagic, WASMagicFlags } from "../../index";
+import { WASMagic, WASMagicFlags, StdioOverrideFunction } from "../../index";
 
 describe("WASMagic", () => {
   describe("Default magic file", () => {
@@ -49,6 +49,24 @@ describe("WASMagic", () => {
         expect(magicText.detect(fileBuf)).toBe(expectedText);
       },
     );
+
+    test("WASMagic throws when it fails to load", async () => {
+      let err: Error | undefined;
+      try {
+        await WASMagic.create({
+          loadDefaultMagicfile: false,
+          magicFiles: [
+            // To force a loading failure
+            Buffer.from("FOOOOOOOBAR"),
+          ],
+        });
+      } catch (_err) {
+        err = _err as Error;
+      }
+
+      expect(err).toBeInstanceOf(Error);
+      expect(err?.message.startsWith("WASMagic Load Error: ")).toBe(true);
+    });
   });
 
   describe("Specified foobar custom magic file, with default magic file", () => {
@@ -112,4 +130,37 @@ Some made up stuff
       },
     );
   });
+
+  describe("StdioOverrideFunction", () => {
+    describe("StdioOverrideFunction fires when WASMagic fails to load", () => {
+      let stdioType: string | undefined;
+      let text: string | undefined;
+      const stdio: StdioOverrideFunction = (_stdioType, _text) => {
+        stdioType = _stdioType;
+        text = _text;
+      };
+
+      beforeAll(async () => {
+        try {
+          await WASMagic.create({
+            loadDefaultMagicfile: false,
+            magicFiles: [
+              // To force a loading failure
+              Buffer.from("FOOOOOOOBAR"),
+            ],
+            stdio,
+          });
+        } catch (_err) {
+          // Ignoring _err
+        }
+      });
+
+      test("stdioType is a String", () =>
+        expect(typeof stdioType).toBe("string"));
+      test("stdioType is stderr", () => expect(stdioType).toBe("stderr"));
+      test("text is a String", () => expect(typeof text).toBe("string"));
+      test("text is a known error", () =>
+        expect(text).toBe("0, 1: Warning: offset `FOOOOOOOBAR' invalid"));
+    });
+  });
 });