Refactor error handling (#2750)

src/cli-constant.js

@@ -17,6 +17,12 @@ const stringOptionNames = [
   "trailing-comma"
 ];
 
+const defaultOptions = {
+  "bracket-spacing": true,
+  semi: true,
+  parser: "babylon"
+};
+
 const options = {
   boolean: [
     "write",
@@ -45,7 +51,8 @@ const options = {
   ].concat(stringOptionNames),
   default: {
     color: true,
-    "ignore-path": ".prettierignore"
+    "ignore-path": ".prettierignore",
+    "config-precedence": "cli-override"
   },
   alias: {
     help: "h",
@@ -111,6 +118,7 @@ Available options:
 module.exports = {
   booleanOptionNames,
   stringOptionNames,
+  defaultOptions,
   options,
   usage
 };

src/cli-util.js

@@ -61,32 +61,35 @@ function getIntOption(argv, optionName) {
     return Number(value);
   }
 
-  console.error(
+  throw new Error(
     "Invalid --" +
       optionName +
-      " value. Expected an integer, but received: " +
+      " value.\nExpected an integer, but received: " +
       JSON.stringify(value)
   );
-  process.exit(1);
 }
 
 function getTrailingComma(argv) {
-  switch (argv["trailing-comma"]) {
-    case undefined:
-    case "none":
-      return "none";
+  const value = argv["trailing-comma"];
+
+  switch (value) {
     case "":
       console.warn(
         "Warning: `--trailing-comma` was used without an argument. This is deprecated. " +
           'Specify "none", "es5", or "all".'
       );
       return "es5";
+    case undefined:
+      return "none";
+    case "none":
     case "es5":
-      return "es5";
     case "all":
-      return "all";
+      return value;
     default:
-      throw new Error("Invalid option for --trailing-comma");
+      throw new Error(
+        "Invalid option for --trailing-comma.\n" +
+          `Expected "none", "es5" or "all", but received: "${value}"`
+      );
   }
 }
 
@@ -195,41 +198,57 @@ function format(argv, input, opt) {
   return prettier.formatWithCursor(input, opt);
 }
 
-function getOptionsForFile(argv, filePath) {
-  const options =
-    argv["config"] === false ? null : resolver.resolveConfig.sync(filePath);
-
+function getOptionsOrDie(argv, filePath) {
   try {
-    const dashifiedConfig = dashifyObject(options);
-    const parsedArgs = minimist(argv.__args, {
+    return argv["config"] === false
+      ? null
+      : resolver.resolveConfig.sync(filePath);
+  } catch (error) {
+    console.error("Error: Invalid configuration file.");
+    console.error(error.message);
+    process.exit(2);
+  }
+}
+
+function getOptionsForFile(argv, filePath) {
+  const options = getOptionsOrDie(argv, filePath);
+  const configPrecedence = argv["config-precedence"];
+  return applyConfigPrecedence(argv.__args, options, configPrecedence);
+}
+
+function parseArgsToOptions(args, defaults) {
+  return getOptions(
+    minimist(args, {
       boolean: constant.booleanOptionNames,
       string: constant.stringOptionNames,
       default: Object.assign(
-        {
-          semi: true,
-          "bracket-spacing": true,
-          "config-precedence": "cli-override",
-          parser: "babylon"
-        },
-        dashifiedConfig
+        {},
+        constant.defaultOptions,
+        dashifyObject(defaults)
       )
-    });
+    })
+  );
+}
 
-    switch (parsedArgs["config-precedence"]) {
+function applyConfigPrecedence(args, options, configPrecedence) {
+  try {
+    switch (configPrecedence) {
       case "cli-override":
-        return getOptions(parsedArgs);
+        return parseArgsToOptions(args, options);
       case "file-override":
-        return getOptions(Object.assign({}, parsedArgs, dashifiedConfig));
+        return Object.assign({}, parseArgsToOptions(args), options);
       case "prefer-file":
-        if (!options) {
-          return getOptions(parsedArgs);
-        }
-        return getOptions(dashifiedConfig);
+        return options || parseArgsToOptions(args);
+
       default:
-        throw new Error("Invalid option for --config-precedence");
+        throw new Error(
+          "Invalid option for --config-precedence.\n" +
+            'Expected "cli-override", "file-override" or "prefer-file", ' +
+            `but received: "${configPrecedence}"`
+        );
     }
   } catch (error) {
-    console.error("Invalid configuration:", error.toString());
+    console.error(error.toString());
     process.exit(2);
   }
 }

tests_integration/__tests__/__snapshots__/config-invalid.js.snap

@@ -1,20 +1,31 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`throw error with invalid config format 1`] = `"Failed to parse \\"<cwd>/tests_integration/cli/config/invalid/file/.prettierrc\\" as JSON, JS, or YAML."`;
+exports[`throw error with invalid config format 1`] = `
+"Error: Invalid configuration file.
+Failed to parse \\"<cwd>/tests_integration/cli/config/invalid/file/.prettierrc\\" as JSON, JS, or YAML.
+"
+`;
 
 exports[`throw error with invalid config option (int) 1`] = `
-"Invalid --tab-width value. Expected an integer, but received: 0.5
+"Error: Invalid --tab-width value.
+Expected an integer, but received: 0.5
 "
 `;
 
 exports[`throw error with invalid config option (trailingComma) 1`] = `
-"Invalid configuration:
+"Error: Invalid option for --trailing-comma.
+Expected \\"none\\", \\"es5\\" or \\"all\\", but received: \\"wow\\"
 "
 `;
 
 exports[`throw error with invalid config precedence option (configPrecedence) 1`] = `
-"Invalid configuration:
+"Error: Invalid option for --config-precedence.
+Expected \\"cli-override\\", \\"file-override\\" or \\"prefer-file\\", but received: \\"option/configPrecedence\\"
 "
 `;
 
-exports[`throw error with invalid config target (directory) 1`] = `"EISDIR: illegal operation on a directory, read"`;
+exports[`throw error with invalid config target (directory) 1`] = `
+"Error: Invalid configuration file.
+EISDIR: illegal operation on a directory, read
+"
+`;