Avoid api calls for exact versions

__tests__/installer.test.ts

@@ -121,13 +121,13 @@ describe('installer tests', () => {
 
   it('Resolving a exact preview version works', async () => {
     const dotnetInstaller = new installer.DotnetCoreInstaller(
-      '5.0.0-preview.4'
+      '5.0.0-preview.6'
     );
     let versInfo = await dotnetInstaller.resolveInfos(
-      new installer.DotNetVersionInfo('5.0.0-preview.4')
+      new installer.DotNetVersionInfo('5.0.0-preview.6')
     );
 
-    expect(versInfo).toBe('5.0.0-preview.4');
+    expect(versInfo).toBe('5.0.0-preview.6');
   }, 100000);
 
   it('Acquires version of dotnet if no matching version is installed', async () => {

dist/index.js

@@ -16723,7 +16723,7 @@ class DotnetCoreInstaller {
         return __awaiter(this, void 0, void 0, function* () {
             let output = '';
             let resultCode = 0;
-            let calculatedVersion = yield this.resolveInfos(new DotNetVersionInfo(this.version));
+            let calculatedVersion = yield this.resolveVersion(new DotNetVersionInfo(this.version));
             var envVariables = {};
             for (let key in process.env) {
                 if (process.env[key]) {
@@ -16792,11 +16792,12 @@ class DotnetCoreInstaller {
             }
         });
     }
-    // OsSuffixes - The suffix which is a part of the file name ex- linux-x64, windows-x86
-    // Type - SDK / Runtime
     // versionInfo - versionInfo of the SDK/Runtime
-    resolveInfos(versionInfo) {
+    resolveVersion(versionInfo) {
         return __awaiter(this, void 0, void 0, function* () {
+            if (versionInfo.isExactVersion()) {
+                return versionInfo.version();
+            }
             const httpClient = new hc.HttpClient('actions/setup-dotnet', [], {
                 allowRetries: true,
                 maxRetries: 3
@@ -16810,14 +16811,15 @@ class DotnetCoreInstaller {
                     semver.satisfies(releaseInfo['sdk']['version-display'], versionInfo.version()));
             });
             // Exclude versions that are newer than the latest if using not exact
-            if (!versionInfo.isExactVersion()) {
             let latestSdk = releasesResult['latest-sdk'];
             releasesInfo = releasesInfo.filter((releaseInfo) => semver.lte(releaseInfo['sdk']['version'], latestSdk));
-            }
             // Sort for latest version
             releasesInfo = releasesInfo.sort((a, b) => semver.rcompare(a['sdk']['version'], b['sdk']['version']));
-            let selectedVersion = releasesInfo[0]['sdk']['version'];
+            if (releasesInfo.length == 0) {
-            return selectedVersion;
+                throw `Could not construct download URL. Please ensure that specified version ${versionInfo.version()} is valid.`;
+            }
+            let release = releasesInfo[0];
+            return release['sdk']['version'];
         });
     }
     getReleasesJsonUrl(httpClient, versionParts) {

src/installer.ts

@@ -96,7 +96,7 @@ export class DotnetCoreInstaller {
     let output = '';
     let resultCode = 0;
 
-    let calculatedVersion = await this.resolveInfos(
+    let calculatedVersion = await this.resolveVersion(
       new DotNetVersionInfo(this.version)
     );
 
@@ -178,10 +178,12 @@ export class DotnetCoreInstaller {
     }
   }
 
-  // OsSuffixes - The suffix which is a part of the file name ex- linux-x64, windows-x86
-  // Type - SDK / Runtime
   // versionInfo - versionInfo of the SDK/Runtime
-  async resolveInfos(versionInfo: DotNetVersionInfo): Promise<string> {
+  async resolveVersion(versionInfo: DotNetVersionInfo): Promise<string> {
+    if (versionInfo.isExactVersion()) {
+      return versionInfo.version();
+    }
+
     const httpClient = new hc.HttpClient('actions/setup-dotnet', [], {
       allowRetries: true,
       maxRetries: 3
@@ -209,22 +211,23 @@ export class DotnetCoreInstaller {
     });
 
     // Exclude versions that are newer than the latest if using not exact
-    if (!versionInfo.isExactVersion()) {
     let latestSdk: string = releasesResult['latest-sdk'];
 
     releasesInfo = releasesInfo.filter((releaseInfo: any) =>
       semver.lte(releaseInfo['sdk']['version'], latestSdk)
     );
-    }
 
     // Sort for latest version
     releasesInfo = releasesInfo.sort((a, b) =>
       semver.rcompare(a['sdk']['version'], b['sdk']['version'])
     );
 
-    let selectedVersion = releasesInfo[0]['sdk']['version'];
+    if (releasesInfo.length == 0) {
+      throw `Could not construct download URL. Please ensure that specified version ${versionInfo.version()} is valid.`;
+    }
 
-    return selectedVersion;
+    let release = releasesInfo[0];
+    return release['sdk']['version'];
   }
 
   private async getReleasesJsonUrl(