Infer version from MANIFEST.MF if mod uses version wildcard.

src/model/struct/model/module/forgemod/forgemod113.struct.ts

@@ -8,6 +8,8 @@ import { BaseForgeModStructure } from '../forgemod.struct'
 
 export class ForgeModStructure113 extends BaseForgeModStructure {
 
+    public static readonly IMPLEMENTATION_VERSION_REGEX = /^Implementation-Version: (.+)[\r\n]/
+
     public static isForVersion(version: string) {
         return VersionUtil.isVersionAcceptable(version, [13, 14, 15])
     }
@@ -73,7 +75,26 @@ export class ForgeModStructure113 extends BaseForgeModStructure {
             if (raw) {
                 // Assuming the main mod will be the first entry in this file.
                 try {
-                    this.forgeModMetadata[name] = toml.parse(raw) as ModsToml
+                    const parsed = toml.parse(raw) as ModsToml
+
+                    // tslint:disable-next-line: no-invalid-template-strings
+                    if (parsed.mods[0].version === '${file.jarVersion}') {
+                        let version = '0.0.0'
+                        const manifest = zip.readAsText('META-INF/MANIFEST.MF')
+                        const keys = manifest.split('\n')
+                        console.log(keys)
+                        for (const key of keys) {
+                            const match = ForgeModStructure113.IMPLEMENTATION_VERSION_REGEX.exec(key)
+                            if (match != null) {
+                                version = match[1]
+                            }
+                        }
+                        console.debug(`ForgeMod ${name} contains a version wildcard, inferring ${version}`)
+                        parsed.mods[0].version = version
+                    }
+
+                    this.forgeModMetadata[name] = parsed
+
                 } catch (err) {
                     console.error(`ForgeMod ${name} contains an invalid mods.toml file.`)
                     createDefault = true