Unarchiver knows what tools it needs to install

README.md

@@ -16,7 +16,7 @@ Change how your team works.
  
 
 
-# tea/cli 0.3.9
+# tea/cli 0.4.0
 
 tea is a universal virtual‑environment manager:
 

src/prefab/resolve.ts

@@ -18,7 +18,7 @@ export default async function resolve(reqs: PackageRequirement[]): Promise<Packa
     } else {
       const versions = await inventory.getVersions({ project, constraint })
       const version = semver.maxSatisfying(versions, constraint)
-      if (!version) throw "no-version"
+      if (!version) { console.error({ project, constraint, versions }); throw new Error() }
       rv.push({ version, project })
     }
   }

src/utils/Unarchiver.ts

@@ -1,4 +1,4 @@
-import { Path, Verbosity } from "types"
+import { PackageRequirement, Path, Verbosity, semver } from "types"
 
 interface Options {
   dstdir: Path
@@ -20,8 +20,14 @@ export class Unarchiver {
   supports(_filename: Path): boolean {
     return false
   }
+
+  dependencies(): PackageRequirement[] {
+    return []
+  }
 }
 
+const constraint = new semver.Range("*")
+
 export class TarballUnarchiver extends Unarchiver {
   private stripComponents?: number
 
@@ -51,6 +57,30 @@ export class TarballUnarchiver extends Unarchiver {
       return false
     }
   }
+
+  dependencies() {
+    const rv = [{
+      project: "gnu.org/tar",
+      constraint
+    }]
+    switch (this.opts.zipfile.extname()) {
+    case ".tbz":
+    case ".tar.bz2":
+      rv.push({
+        project: "sourceware.org/bzip2",
+        constraint
+      })
+      break
+    case ".txz":
+    case ".tar.xz":
+      rv.push({
+        project: "tukaani.org/xz",
+        constraint
+      })
+      break
+    }
+    return rv
+  }
 }
 
 export class ZipUnarchiver extends Unarchiver {
@@ -76,4 +106,11 @@ export class ZipUnarchiver extends Unarchiver {
   static supports(filename: Path): boolean {
     return filename.extname() == ".zip"
   }
+
+  dependencies() {
+    return [{
+      project: "info-zip.org/unzip",
+      constraint
+    }]
+  }
 }