Feature add magic flags (#32)

Closes #30

In order to allow more extensive usage of LibMagic we now expose the
Flags (https://github.com/file/file/blob/46da4cf/src/magic.h.in#L32).
Where the default is to use `MAGIC_MIME_TYPE`.

- Force UTC Timezone for tests. This avoids errors when GitHub runner
  are running in another timezone

Co-authored-by: Warnar Boekkooi <[email protected]>

Makefile

@@ -8,7 +8,7 @@ num_processors := $(shell nproc || printf "1")
 export EMCC_CFLAGS = -msimd128 -O2
 
 test: dist/index.js dist/test/integration/foobar_magic dist/test/integration/png_magic dist/test/integration/jpeg_magic
-	npm run test
+	TZ='UTC' npm run test
 
 dist/test/integration/foobar_magic dist/test/integration/png_magic dist/test/integration/jpeg_magic &:
 	mkdir -p dist/test/integration \

README.md

@@ -17,19 +17,21 @@ provides accurate filetype detection with zero prod dependencies.
 npm install wasmagic
 ```
 
-Detect the mime of something:
+Detect the mime and encoding of something:
 
 ```javascript
-const { WASMagic } = require("wasmagic");
+const { WASMagic, WASMagicFlags } = require("wasmagic");
 
 async function main() {
-  const magic = await WASMagic.create();
+  const magic = await WASMagic.create({
+    flags: WASMagicFlags.MIME_TYPE | WASMagicFlags.MIME_ENCODING,
+  });
   const pngFile = Buffer.from("89504E470D0A1A0A0000000D49484452", "hex");
   console.log(magic.getMime(pngFile));
 }
 
 main().catch((err) => console.error(err));
-// outputs: image/png
+// outputs: image/png; charset=binary
 ```
 
 ### Options
@@ -45,6 +47,7 @@ tests](src/test/integration/index.ts).
 
 ```typescript
 type WASMagicOptions = {
+  flags?: WASMagicFlags;
   loadDefaultMagicfile?: boolean;
   magicFiles?: Uint8Array[];
   stdio?: (stdioName: "stdout" | "stderr", text: string) => void;
@@ -55,12 +58,22 @@ Default options:
 
 ```typescript
 {
+  flags: WASMagicFlags.MIME_TYPE,
   loadDefaultMagicfile: true,
   magicFiles: [],
   stdio: (_stdioName: "stdout" | "stderr", _text: string) => {},
 }
 ```
 
+##### `flags`
+
+`flags` control `libmagic` behavior. To use the flags, import the `enum` from
+the module, [per the example above](#usage).
+
+[Please refer to the code for the flag definitions](src/index.ts#L5)
+
+**Default**: `WASMagicFlags.MIME_TYPE`
+
 ##### `loadDefaultMagicfile`
 
 `loadDefaultMagicFile` is a `boolean` dictates whether or not to load the

src/index.ts

@@ -2,19 +2,81 @@ import libmagicFactory from "../dist/libmagic-wrapper";
 
 declare function wrappedGetMime(bufPointer: number, bufLength: number): string;
 
+export enum WASMagicFlags {
+  /** No flags */
+  NONE = 0x0000000,
+  /** Turn on debugging */
+  DEBUG = 0x0000001,
+  /** Follow symlinks */
+  SYMLINK = 0x0000002,
+  /** Check inside compressed files */
+  COMPRESS = 0x0000004,
+  /** Look at the contents of devices */
+  DEVICES = 0x0000008,
+  /** Return the MIME type */
+  MIME_TYPE = 0x0000010,
+  /** Return all matches */
+  CONTINUE = 0x0000020,
+  /** Print warnings to stderr */
+  CHECK = 0x0000040,
+  /** Restore access time on exit */
+  PRESERVE_ATIME = 0x0000080,
+  /** Don't convert unprintable chars */
+  RAW = 0x0000100,
+  /** Handle ENOENT etc as real errors */
+  ERROR = 0x0000200,
+  /** Return the MIME encoding */
+  MIME_ENCODING = 0x0000400,
+  /** Return the Apple creator/type */
+  APPLE = 0x0000800,
+  /** Return a /-separated list of extensions */
+  EXTENSION = 0x1000000,
+  /** Check inside compressed files but not report compression */
+  COMPRESS_TRANSP = 0x2000000,
+  /** Don't allow decompression that needs to fork */
+  NO_COMPRESS_FORK = 0x4000000,
+  /** Don't check for compressed files */
+  NO_CHECK_COMPRESS = 0x0001000,
+  /** Don't check for tar files */
+  NO_CHECK_TAR = 0x0002000,
+  /** Don't check magic entries */
+  NO_CHECK_SOFT = 0x0004000,
+  /** Don't check application type */
+  NO_CHECK_APPTYPE = 0x0008000,
+  /** Don't check for elf details */
+  NO_CHECK_ELF = 0x0010000,
+  /** Don't check for text files */
+  NO_CHECK_TEXT = 0x0020000,
+  /** Don't check for cdf files */
+  NO_CHECK_CDF = 0x0040000,
+  /** Don't check for CSV files */
+  NO_CHECK_CSV = 0x0080000,
+  /** Don't check tokens */
+  NO_CHECK_TOKENS = 0x0100000,
+  /** Don't check text encodings */
+  NO_CHECK_ENCODING = 0x0200000,
+  /** Don't check for JSON files */
+  NO_CHECK_JSON = 0x0400000,
+  /** Don't check for SIMH tape files */
+  NO_CHECK_SIMH = 0x0800000,
+}
+
 export type WASMagicOptions = {
+  flags?: WASMagicFlags;
   loadDefaultMagicfile?: boolean;
   magicFiles?: Uint8Array[];
   stdio?: StdioOverrideFunction;
 };
 
 type WASMagicOptionsComplete = {
+  flags: WASMagicFlags;
   loadDefaultMagicfile: boolean;
   magicFiles: Uint8Array[];
   stdio: StdioOverrideFunction;
 };
 
 const defaultWASMagicOptions: WASMagicOptionsComplete = Object.freeze({
+  flags: WASMagicFlags.MIME_TYPE,
   loadDefaultMagicfile: true,
   magicFiles: [],
   stdio: (_stdioName: "stdout" | "stderr", _text: string) => {},
@@ -52,8 +114,8 @@ export class WASMagic {
     const loadErr = Module.ccall(
       "magic_wrapper_load",
       "string",
-      ["string"],
-      [magicPaths.join(":")],
+      ["number", "string"],
+      [options.flags, magicPaths.join(":")],
     );
 
     if (loadErr !== "") {

src/libmagic-wrapper.c

@@ -4,13 +4,14 @@
 struct magic_set *ms = NULL;
 
 const char* magic_wrapper_load(
+  int flags,
   char* magic_paths
 ) {
   if (ms != NULL) {
     return "Load called multiple times";
   }
 
-  ms = magic_open(0 | MAGIC_MIME_TYPE);
+  ms = magic_open(flags);
   if (magic_load(ms, magic_paths) == -1) {
     return magic_error(ms);
   }