initial attempt at nix flake

flake.lock

@@ -0,0 +1,42 @@
+{
+  "nodes": {
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1649676176,
+        "narHash": "sha256-OWKJratjt2RW151VUlJPRALb7OU2S5s+f0vLj4o1bHM=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "a4b154ebbdc88c8498a5c7b01589addc9e9cb678",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1651726670,
+        "narHash": "sha256-dSGdzB49SEvdOJvrQWfQYkAefewXraHIV08Vz6iDXWQ=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "c777cdf5c564015d5f63b09cc93bef4178b19b01",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "rev": "c777cdf5c564015d5f63b09cc93bef4178b19b01",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,60 @@
+{
+  description = "An implementation of the Double Ratchet cryptographic ratchet";
+
+  inputs.nixpkgs.url = "nixpkgs/c777cdf5c564015d5f63b09cc93bef4178b19b01";
+  # c777cdf5c564015d5f63b09cc93bef4178b19b01 is current unstable.  We can't use
+  # the current stable release because of
+  # https://github.com/emscripten-core/emscripten/issues/14995
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs = { self, nixpkgs, flake-utils }:
+   (
+      flake-utils.lib.eachDefaultSystem (system:
+        let
+          pkgs = import nixpkgs {
+            inherit system;
+          };
+        in
+          rec {
+            packages.javascript = pkgs.buildEmscriptenPackage {
+              name = "olm";
+
+              buildInputs = [ pkgs.gnumake pkgs.python3 pkgs.yarn ];
+
+              src = ./.;
+
+              configurePhase = "";
+
+              buildPhase = ''
+                export EM_CACHE=$TMPDIR
+                make javascript/exported_functions.json
+                make js
+              '';
+
+              output = [ "out" ];
+
+              installPhase = ''
+                mkdir -p $out/javascript
+                cd javascript
+                echo sha256: > checksums.txt
+	              sha256sum olm.js olm_legacy.js olm.wasm >> checksums.txt
+	              echo sha512: >> checksums.txt
+	              sha512sum olm.js olm_legacy.js olm.wasm >> checksums.txt
+                cp package.json olm.js olm.wasm olm_legacy.js index.d.ts README.md checksums.txt $out/javascript
+                cd ..
+              '';
+
+              checkPhase = ''
+                cd javascript
+                export HOME=$TMPDIR
+                yarn install
+                yarn test
+                cd ..
+              '';
+            };
+
+            defaultPackage = packages.javascript;
+          }
+      )
+   );
+}