feat: add support for the fnm version manager

* refactor

* feat: implements fnm support

* fix tests maybe

* fix: fnm windows path

Author: connor4312

src/dap/errors.ts

@@ -65,7 +65,7 @@ export function createUserError(text: string, code = ErrorCodes.UserError): Dap.
 export const nvmNotFound = () =>
   createUserError(
     l10n.t(
-      "Attribute 'runtimeVersion' requires Node.js version manager 'nvs' or 'nvm' to be installed.",
+      "Attribute 'runtimeVersion' requires Node.js version manager 'nvs', 'nvm' or 'fnm' to be installed.",
     ),
     ErrorCodes.NvmOrNvsNotFound,
   );

src/targets/node/nvmResolver.ts

@@ -36,6 +36,7 @@ const enum Vars {
   NvsHome = 'NVS_HOME',
   WindowsNvmHome = 'NVM_HOME',
   UnixNvmHome = 'NVM_DIR',
+  FnmHome = 'FNM_DIR',
 }
 
 @injectable()
@@ -49,6 +50,10 @@ export class NvmResolver implements INvmResolver {
   ) {}
 
   public async resolveNvmVersionPath(version: string) {
+    let directory: string | undefined = undefined;
+    const versionManagers: string[] = [];
+    const versionData = this.parseVersionString(version);
+
     let nvsHome = this.env[Vars.NvsHome];
     if (!nvsHome) {
       // NVS_HOME is not always set. Probe for 'nvs' directory instead
@@ -61,9 +66,6 @@ export class NvmResolver implements INvmResolver {
       }
     }
 
-    let directory: string | undefined = undefined;
-    const versionManagers: string[] = [];
-    const versionData = this.parseVersionString(version);
     if (versionData.nvsFormat || nvsHome) {
       directory = await this.resolveNvs(nvsHome, versionData);
       if (!directory && versionData.nvsFormat) {
@@ -87,6 +89,17 @@ export class NvmResolver implements INvmResolver {
       }
     }
 
+    if (!directory) {
+      const fnmDir =
+        this.platform === 'win32'
+          ? this.env[Vars.FnmHome] || path.join(this.env['APPDATA'] || '', 'fnm')
+          : this.env[Vars.FnmHome] || path.join(this.homedir, '.fnm');
+      if (await this.fsUtils.exists(fnmDir)) {
+        directory = await this.resolveFnm(version, fnmDir);
+        versionManagers.push('fnm');
+      }
+    }
+
     if (!versionManagers.length) {
       throw new ProtocolError(nvmNotFound());
     }
@@ -160,6 +173,19 @@ export class NvmResolver implements INvmResolver {
     return this.findBinFolderForVersion(nvmHome, `v${version}`);
   }
 
+  private async resolveFnm(version: string, fnmHome: string) {
+    const directory = this.findBinFolderForVersion(
+      path.join(fnmHome, 'node-versions'),
+      `v${version}`,
+    );
+
+    if (!directory) return;
+
+    return this.platform === 'win32'
+      ? path.join(directory, 'installation')
+      : path.join(directory, 'installation', 'bin');
+  }
+
   private findBinFolderForVersion(
     dir: string,
     version: string,

src/test/node/runtimeVersion.test.ts

@@ -30,11 +30,16 @@ describe('runtimeVersion', () => {
         'nvs/node/13.12.0/x64/bin/node': '',
         'nvs/node/13.11.0/x86/bin/node': '',
         'nvm/versions/node/v13.11.0/bin/node': '',
+        'fnm/node-versions/v13.10.0/installation/bin/node': '',
       });
 
       resolver = new NvmResolver(
         fsUtils,
-        { NVS_HOME: path.join(testFixturesDir, 'nvs'), NVM_DIR: path.join(testFixturesDir, 'nvm') },
+        {
+          NVS_HOME: path.join(testFixturesDir, 'nvs'),
+          NVM_DIR: path.join(testFixturesDir, 'nvm'),
+          FNM_DIR: path.join(testFixturesDir, 'fnm'),
+        },
         'x64',
         'linux',
         testWorkspace,
@@ -48,9 +53,12 @@ describe('runtimeVersion', () => {
       const { directory: b } = await resolver.resolveNvmVersionPath('13.11');
       expect(b).to.equal(path.join(testFixturesDir, 'nvm/versions/node/v13.11.0/bin'));
 
+      const { directory: c } = await resolver.resolveNvmVersionPath('13.10');
+      expect(c).to.equal(path.join(testFixturesDir, 'fnm/node-versions/v13.10.0/installation/bin'));
+
       await expect(resolver.resolveNvmVersionPath('14')).to.eventually.be.rejectedWith(
         ProtocolError,
-        /not installed using version manager nvs\/nvm/,
+        /not installed using version manager nvs\/nvm\/fnm/,
       );
     });
 
@@ -229,4 +237,44 @@ describe('runtimeVersion', () => {
       );
     });
   });
+
+  describe('fnm', () => {
+    beforeEach(() => {
+      createFileTree(testFixturesDir, {
+        'node-versions/v13.12.0/installation/bin/node': '',
+        'node-versions/v13.3.0/installation/bin/node': '',
+        'node-versions/v13.invalid/installation/bin/node': '',
+      });
+
+      resolver = new NvmResolver(
+        fsUtils,
+        { FNM_DIR: testFixturesDir },
+        'x64',
+        'linux',
+        testWorkspace,
+      );
+    });
+
+    it('gets an exact match', async () => {
+      const { directory, binary } = await resolver.resolveNvmVersionPath('13.3.0');
+      expect(directory).to.equal(
+        path.join(testFixturesDir, 'node-versions/v13.3.0/installation/bin'),
+      );
+      expect(binary).to.equal('node');
+    });
+
+    it('gets the best matching version', async () => {
+      const { directory } = await resolver.resolveNvmVersionPath('13');
+      expect(directory).to.equal(
+        path.join(testFixturesDir, 'node-versions/v13.12.0/installation/bin'),
+      );
+    });
+
+    it('throws if no version match', async () => {
+      await expect(resolver.resolveNvmVersionPath('14')).to.eventually.be.rejectedWith(
+        ProtocolError,
+        /not installed/,
+      );
+    });
+  });
 });