Add `yaml-to-dhall`

2 files changed, 10 insertions, 2 deletions

diff --git a/package.json b/package.json
index 88b0204..71a1cdb 100644
--- a/package.json
+++ b/package.json
@@ -15,7 +15,8 @@
   "bin": {
     "dhall-to-json": "bin/dhall-to-json.exe",
     "dhall-to-yaml": "bin/dhall-to-yaml.exe",
-    "json-to-dhall": "bin/json-to-dhall.exe"
+    "json-to-dhall": "bin/json-to-dhall.exe",
+    "yaml-to-dhall": "bin/yaml-to-dhall.exe"
   },
   "scripts": {
     "preinstall": "node ./preinstall.js"
diff --git a/preinstall.js b/preinstall.js
index 01db9e0..d53bca2 100644
--- a/preinstall.js
+++ b/preinstall.js
@@ -59,9 +59,16 @@ const readVersion = name =>
 
 const dhallVersion = readVersion("dhall");
 const dhallJsonVersion = readVersion("dhall-json");
-if (semver.valid(dhallJsonVersion) && semver.lt(dhallJsonVersion, "1.2.8")) {
+
+const isLowerThan = (version, upperBound) =>
+  semver.valid(version) && semver.lt(version, upperBound);
+
+if (isLowerThan(dhallJsonVersion, "1.2.8")) {
   throw new Error(`This release of the \`${pkg.name}\` npm package installs \`json-to-dhall\`, which isn’t provided by \`dhall-json@<1.2.8\`.`);
 }
+if (isLowerThan(dhallJsonVersion, "1.3.0")) {
+  throw new Error(`This release of the \`${pkg.name}\` npm package installs \`yaml-to-dhall\`, which isn’t provided by \`dhall-json@<1.3.0\`.`);
+}
 
 const release = `https://github.com/dhall-lang/dhall-haskell/releases/download/${dhallVersion}/dhall-json-${dhallJsonVersion}`;