Fix: Extension version fallback to github support for `~` and `^` (#4099)

* Fix github fallback package with range

* Wip

* Wip

* ./

common/changes/@autorest/configuration/fix-extension-range-github_2021-04-26-16-35.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@autorest/configuration",
+      "comment": "**Bump** @autorest/java default version to 4.0.24",
+      "type": "patch"
+    }
+  ],
+  "packageName": "@autorest/configuration",
+  "email": "tiguerin@microsoft.com"
+}

common/changes/@azure-tools/extension/fix-extension-range-github_2021-04-26-16-34.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "packageName": "@azure-tools/extension",
+      "comment": "**Fix** Fallback to github release when version doesn't exists broken if using version range",
+      "type": "patch"
+    }
+  ],
+  "packageName": "@azure-tools/extension",
+  "email": "tiguerin@microsoft.com"
+}

packages/libs/configuration/resources/plugin-java.md

@@ -2,17 +2,17 @@
 
 The V3 version of the Java Generator.
 
-``` yaml $(java) && !$(legacy) && !$(v2) && !isRequested('@microsoft.azure/autorest.java')
+```yaml $(java) && !$(legacy) && !$(v2) && !isRequested('@microsoft.azure/autorest.java')
 version: ~3.1.0
 
 use-extension:
-  "@autorest/java": "^4.0.4"
+  "@autorest/java": "^4.0.24"
 try-require: ./readme.java.md
 ```
 
 Enable use of the V2 Java generator (and V2 core) with the `--legacy` or `--v2` parameter:
 
-``` yaml $(java) && ($(legacy) || $(v2) || isRequested('@microsoft.azure/autorest.java'))
+```yaml $(java) && ($(legacy) || $(v2) || isRequested('@microsoft.azure/autorest.java'))
 # default the v2 generator to using the last stable @microsoft.azure/autorest-core
 version: ~2.0.4413
 

packages/libs/extension/src/main.ts

@@ -232,13 +232,13 @@ export class ExtensionManager {
       // (if it is an autorest.<whatever> project)
       // https://github.com/Azure/${PROJECT}/releases/download/v${VERSION}/autorest/${PROJECT}-${VERSION}.tgz
       if (name.startsWith("@autorest/")) {
-        const ghurl = `https://github.com/Azure/${name.replace(
-          "@autorest/",
-          "autorest.",
-        )}/releases/download/v${version}/${name.replace("@", "").replace("autorest/", "autorest-")}-${version.replace(
-          /_/g,
-          "-",
-        )}.tgz`;
+        const githubRepo = name.replace("@autorest/", "autorest.");
+        const githubPkgName = name.replace("@", "").replace("autorest/", "autorest-");
+        const githubVersion = version
+          .replace(/^[~|^]/g, "") // Use the exact version instead of range
+          .replace(/_/g, "-"); // Replace _ with - ;
+
+        const ghurl = `https://github.com/Azure/${githubRepo}/releases/download/v${githubVersion}/${githubPkgName}-${githubVersion}.tgz`;
         try {
           const pm = await fetchPackageMetadata(ghurl);
           if (pm) {