Allow plugins to provide completions for non-dart files

pkg/analysis_server/lib/src/domain_completion.dart

Index: pkg/analysis_server/lib/src/domain_completion.dart
diff --git a/pkg/analysis_server/lib/src/domain_completion.dart b/pkg/analysis_server/lib/src/domain_completion.dart
index e015a40acacf0af45655680c0fbabda42a7974a8..a00617f22f630dbfa41cec09a5e82fe4a60abbf3 100644
--- a/pkg/analysis_server/lib/src/domain_completion.dart
+++ b/pkg/analysis_server/lib/src/domain_completion.dart
@@ -87,26 +87,28 @@ class CompletionDomainHandler extends AbstractRequestHandler {
     //
     // Compute completions generated by server.
     //
-    Iterable<CompletionContributor> newContributors =
-        server.serverPlugin.completionContributors;
     List<CompletionSuggestion> suggestions = <CompletionSuggestion>[];
-
-    const COMPUTE_SUGGESTIONS_TAG = 'computeSuggestions';
-    performance.logStartTime(COMPUTE_SUGGESTIONS_TAG);
-
-    for (CompletionContributor contributor in newContributors) {
-      String contributorTag = 'computeSuggestions - ${contributor.runtimeType}';
-      performance.logStartTime(contributorTag);
-      try {
-        suggestions.addAll(await contributor.computeSuggestions(request));
-      } on AbortCompletion {
-        suggestions.clear();
-        break;
+    if (request.result != null) {
+      Iterable<CompletionContributor> newContributors =
+          server.serverPlugin.completionContributors;
+
+      const COMPUTE_SUGGESTIONS_TAG = 'computeSuggestions';
+      performance.logStartTime(COMPUTE_SUGGESTIONS_TAG);
+
+      for (CompletionContributor contributor in newContributors) {
+        String contributorTag = 'computeSuggestions - ${contributor
+            .runtimeType}';
+        performance.logStartTime(contributorTag);
+        try {
+          suggestions.addAll(await contributor.computeSuggestions(request));
+        } on AbortCompletion {
+          suggestions.clear();
+          break;
+        }
+        performance.logElapseTime(contributorTag);
       }
-      performance.logElapseTime(contributorTag);
+      performance.logElapseTime(COMPUTE_SUGGESTIONS_TAG);
     }
-    performance.logElapseTime(COMPUTE_SUGGESTIONS_TAG);
-
     // TODO (danrubel) if request is obsolete (processAnalysisRequest returns
     // false) then send empty results
 
@@ -161,8 +163,11 @@ class CompletionDomainHandler extends AbstractRequestHandler {
     // extract and validate params
     CompletionGetSuggestionsParams params =
         new CompletionGetSuggestionsParams.fromRequest(request);
+    String filePath = params.file;
+    int offset = params.offset;
 
-    AnalysisResult result = await server.getAnalysisResult(params.file);
+    AnalysisResult result = await server.getAnalysisResult(filePath);
+    Source source;
 
     if (result == null || !result.exists) {
       if (server.onNoAnalysisCompletion != null) {
@@ -170,31 +175,27 @@ class CompletionDomainHandler extends AbstractRequestHandler {
         await server.onNoAnalysisCompletion(
             request, this, params, performance, completionId);
         return;
-      } else {
-        server.sendResponse(new Response.unknownSource(request));
+      }
+      source = server.resourceProvider.getFile(filePath).createSource();
+    } else {
+      if (offset < 0 || offset > result.content.length) {
+        server.sendResponse(new Response.invalidParameter(
+            request,
+            'params.offset',
+            'Expected offset between 0 and source length inclusive,'
+            ' but found ${offset}'));
         return;
       }
-    }
+      source =
+          server.resourceProvider.getFile(result.path).createSource(result.uri);
 
-    if (params.offset < 0 || params.offset > result.content.length) {
-      server.sendResponse(new Response.invalidParameter(
-          request,
-          'params.offset',
-          'Expected offset between 0 and source length inclusive,'
-          ' but found ${params.offset}'));
-      return;
+      recordRequest(performance, source, result.content, offset);
     }
-
-    Source source =
-        server.resourceProvider.getFile(result.path).createSource(result.uri);
-
-    recordRequest(performance, source, result.content, params.offset);
-
     CompletionRequestImpl completionRequest = new CompletionRequestImpl(
         result,
         server.resourceProvider,
         source,
-        params.offset,
+        offset,
         performance,
         server.ideOptions);