chore: improve readme (#74)

Author: lucacasonato

README.md

@@ -54,14 +54,22 @@ Targets the latest major, minor and patch version of Deno.
     deno-version: e7b7129b7a92b7500ded88f8f5baa25a7f59e56e
 ```
 
-### Release candidate
+### Latest release candidate
 
 ```yaml
 - uses: denoland/setup-deno@v1
   with:
     deno-version: rc
 ```
 
+### Specific release candidate
+
+```yaml
+- uses: denoland/setup-deno@v1
+  with:
+    deno-version: 2.0.0-rc.1
+```
+
 ### Version from file
 
 The extension can also automatically read the version file from
@@ -84,8 +92,44 @@ The extension can also automatically read the file from
 
 ### Specifying binary name
 
+This is useful when you want to install different versions of Deno side by side.
+
 ```yaml
 - uses: denoland/setup-deno@v1
   with:
-    deno-binary-name: deno_latest
+    deno-version: canary
+    deno-binary-name: deno_canary
+```
+
+### Determining the release channel
+
+You can determine the release channel reading back the `release-channel` output.
+
+Valid values are `stable`, `canary` and `rc`.
+
+```yaml
+- uses: denoland/setup-deno@v1
+  id: deno
+  with:
+    deno-version: canary
+
+- run: echo "Deno release channel is ${{ steps.deno.outputs.release-channel }}"
+```
+
+### Determining the installed version
+
+You can determine the installed version reading back the `deno-version` output.
+
+For canary versions, the output will be in the form `0.0.0-GIT_HASH`.
+
+For stable and rc versions, the output will be the regular semver version
+number.
+
+```yaml
+- uses: denoland/setup-deno@v1
+  id: deno
+  with:
+    deno-version: canary
+
+- run: echo "Deno version is ${{ steps.deno.outputs.deno-version }}"
 ```

src/version.mjs

@@ -7,13 +7,13 @@ const GIT_HASH_RE = /^[0-9a-fA-F]{40}$/;
 /**
  * @typedef VersionRange
  * @property {string} range
- * @property {"canary" | "rc" | "release"} kind
+ * @property {"canary" | "rc" | "stable"} kind
  */
 
 /**
  * @typedef Version
  * @property {string} version
- * @property {"canary" | "rc" | "release"} kind
+ * @property {"canary" | "rc" | "stable"} kind
  */
 
 /**
@@ -35,7 +35,7 @@ export function parseVersionRange(version) {
   }
 
   if (version === "latest") {
-    return { range: "latest", kind: "release" };
+    return { range: "latest", kind: "stable" };
   }
 
   if (GIT_HASH_RE.test(version)) {
@@ -44,7 +44,7 @@ export function parseVersionRange(version) {
 
   const range = semver.validRange(version);
   if (range !== null) {
-    return { range, kind: "release" };
+    return { range, kind: "stable" };
   }
 
   return null;
@@ -154,7 +154,7 @@ async function resolveRelease(range) {
     if (version === null) {
       throw new Error("Failed to parse release version.");
     }
-    return { version, kind: "release" };
+    return { version, kind: "stable" };
   } else {
     const res = await fetchWithRetries("https://deno.com/versions.json");
     if (res.status !== 200) {
@@ -182,7 +182,7 @@ async function resolveRelease(range) {
     version = semver.clean(version);
     if (version === null) throw new Error("UNREACHABLE");
 
-    return { version, kind: "release" };
+    return { version, kind: version.includes("-rc.") ? "rc" : "stable" };
   }
 }