Merge pull request #131 from github/languages_error

Improve error messages when no languages or no queries are specified

src/config-utils.test.ts

@@ -224,7 +224,9 @@ test("default queries are used", async t => {
         resolveQueriesArgs.push({queries, extraSearchPath});
         return {
           byLanguage: {
-            'javascript': {},
+            'javascript': {
+              'foo.ql': {},
+            },
           },
           noDeclaredLanguage: {},
           multipleDeclaredLanguages: {},
@@ -262,7 +264,11 @@ test("API client used when reading remote config", async t => {
     CodeQL.setCodeQL({
       resolveQueries: async function() {
         return {
-          byLanguage: {},
+          byLanguage: {
+            'javascript': {
+              'foo.ql': {},
+            },
+          },
           noDeclaredLanguage: {},
           multipleDeclaredLanguages: {},
         };

src/config-utils.ts

@@ -452,6 +452,9 @@ async function getLanguagesInRepo(): Promise<string[]> {
  * The result is obtained from the action input parameter 'languages' if that
  * has been set, otherwise it is deduced as all languages in the repo that
  * can be analysed.
+ *
+ * If no languages could be detected from either the workflow or the repository
+ * then throw an error.
  */
 async function getLanguages(): Promise<string[]> {
 
@@ -468,6 +471,13 @@ async function getLanguages(): Promise<string[]> {
     core.info("Automatically detected languages: " + JSON.stringify(languages));
   }
 
+  // If the languages parameter was not given and no languages were
+  // detected then fail here as this is a workflow configuration error.
+  if (languages.length === 0) {
+    throw new Error("Did not detect any languages to analyze. " +
+        "Please update input in workflow or check that GitHub detects the correct languages in your repository.");
+  }
+
   return languages;
 }
 
@@ -515,11 +525,6 @@ async function loadConfig(configFile: string): Promise<Config> {
   }
 
   const languages = await getLanguages();
-  // If the languages parameter was not given and no languages were
-  // detected then fail here as this is a workflow configuration error.
-  if (languages.length === 0) {
-    throw new Error("Did not detect any languages to analyze. Please update input in workflow.");
-  }
 
   const queries = {};
   const pathsIgnore: string[] = [];
@@ -572,6 +577,15 @@ async function loadConfig(configFile: string): Promise<Config> {
     });
   }
 
+  // The list of queries should not be empty for any language. If it is then
+  // it is a user configuration error.
+  for (const language of languages) {
+    if (queries[language] === undefined || queries[language].length === 0) {
+      throw new Error(`Did not detect any queries to run for ${language}. ` +
+          "Please make sure that the default queries are enabled, or you are specifying queries to run.");
+    }
+  }
+
   return {
     languages,
     queries,