fix: build from source instead of npx in GitHub Action

The action now builds the conformance tests from the repo source at the
referenced commit, rather than using npx to download from npm. This means
the action always uses the exact version at the commit it's referenced at,
without needing a published npm package.

Also removes the 'version' input since it's no longer applicable.

Author: maxisbey

README.md

@@ -179,7 +179,6 @@ steps:
 | `scenario`          | No          | Run a single scenario by name                   |
 | `timeout`           | No          | Timeout in ms for client tests (default: 30000) |
 | `verbose`           | No          | Show verbose output (default: false)            |
-| `version`           | No          | Package version to use (default: latest)        |
 | `node-version`      | No          | Node.js version (default: 20)                   |
 
 ## Example Clients

action.yml

@@ -23,9 +23,6 @@ inputs:
     description: 'Timeout in milliseconds for client tests (default: 30000)'
     required: false
     default: '30000'
-  version:
-    description: 'Version of @modelcontextprotocol/conformance to use (default: latest)'
-    required: false
   verbose:
     description: 'Show verbose output (default: false)'
     required: false
@@ -42,14 +39,17 @@ runs:
       with:
         node-version: ${{ inputs.node-version }}
 
+    - name: Build conformance tests
+      shell: bash
+      run: |
+        cd "${{ github.action_path }}"
+        npm ci
+        npm run build
+
     - name: Run conformance tests
       shell: bash
       run: |
-        # Build the npx package specifier
-        PACKAGE="@modelcontextprotocol/conformance"
-        if [ -n "${{ inputs.version }}" ]; then
-          PACKAGE="${PACKAGE}@${{ inputs.version }}"
-        fi
+        CONFORMANCE="${{ github.action_path }}/dist/index.js"
 
         # Build the command arguments
         ARGS="${{ inputs.mode }}"
@@ -93,5 +93,5 @@ runs:
           ARGS="${ARGS} --verbose"
         fi
 
-        echo "Running: npx ${PACKAGE} ${ARGS}"
-        eval "npx -y ${PACKAGE} ${ARGS}"
+        echo "Running: node ${CONFORMANCE} ${ARGS}"
+        eval "node ${CONFORMANCE} ${ARGS}"