improve error message when config is not found

src/analyze-action.ts

@@ -32,6 +32,9 @@ async function run() {
     }
     const logger = getActionsLogger();
     const config = await getConfig(util.getRequiredEnvParam('RUNNER_TEMP'), logger);
+    if (config === undefined) {
+      throw new Error("Config file could not be found at expected location. Has the 'init' action been called?");
+    }
     stats = await runAnalyze(
       parseRepositoryNwo(util.getRequiredEnvParam('GITHUB_REPOSITORY')),
       await util.getCommitOid(),

src/autobuild-action.ts

@@ -45,6 +45,9 @@ async function run() {
     }
 
     const config = await config_utils.getConfig(util.getRequiredEnvParam('RUNNER_TEMP'), logger);
+    if (config === undefined) {
+      throw new Error("Config file could not be found at expected location. Has the 'init' action been called?");
+    }
     language = determineAutobuildLanguage(config, logger);
     if (language !== undefined) {
       await runAutobuild(language, config, logger);

src/config-utils.ts

@@ -854,17 +854,13 @@ async function saveConfig(config: Config, logger: Logger) {
 }
 
 /**
- * Get the config.
- *
- * If this is the first time in a workflow that this is being called then
- * this will parse the config from the user input. The parsed config is then
- * stored to a known location. On the second and further calls, this will
- * return the contents of the parsed config from the known location.
+ * Get the config that has been saved to the given temp dir.
+ * If the config could not be found then returns undefined.
  */
-export async function getConfig(tempDir: string, logger: Logger): Promise<Config> {
+export async function getConfig(tempDir: string, logger: Logger): Promise<Config | undefined> {
   const configFile = getPathToParsedConfigFile(tempDir);
   if (!fs.existsSync(configFile)) {
-    throw new Error("Config file could not be found at expected location. Has the 'init' action been called?");
+    return undefined;
   }
   const configString = fs.readFileSync(configFile, 'utf8');
   logger.debug('Loaded config:');

src/runner.ts

@@ -188,6 +188,10 @@ program
     const logger = getRunnerLogger(cmd.debug);
     try {
       const config = await getConfig(getTempDir(cmd.tempDir), logger);
+      if (config === undefined) {
+        throw new Error("Config file could not be found at expected location. " +
+          "Was the 'init' command run with the same '--temp-dir' argument as this command.");
+      }
       checkEnvironmentSetup(config);
       let language: Language | undefined = undefined;
       if (cmd.language !== undefined) {
@@ -241,6 +245,10 @@ program
       const tempDir = getTempDir(cmd.tempDir);
       const outputDir = cmd.outputDir || path.join(tempDir, 'codeql-sarif');
       const config = await getConfig(getTempDir(cmd.tempDir), logger);
+      if (config === undefined) {
+        throw new Error("Config file could not be found at expected location. " +
+          "Was the 'init' command run with the same '--temp-dir' argument as this command.");
+      }
       checkEnvironmentSetup(config);
       await runAnalyze(
         parseRepositoryNwo(cmd.repository),