New: Codeframe formatter (fixes #5860) (#7437)

Author: vitorbal

index.js

@@ -0,0 +1,121 @@
+/**
+ * @fileoverview Codeframe reporter
+ * @author Vitor Balocco
+ */
+"use strict";
+
+const chalk = require("chalk");
+const codeFrame = require("babel-code-frame");
+const path = require("path");
+
+//------------------------------------------------------------------------------
+// Helpers
+//------------------------------------------------------------------------------
+
+/**
+ * Given a word and a count, append an s if count is not one.
+ * @param   {string} word  A word in its singular form.
+ * @param   {number} count A number controlling whether word should be pluralized.
+ * @returns {string}       The original word with an s on the end if count is not one.
+ */
+function pluralize(word, count) {
+    return (count === 1 ? word : `${word}s`);
+}
+
+/**
+ * Gets a formatted relative file path from an absolute path and a line/column in the file.
+ * @param   {string} filePath The absolute file path to format.
+ * @param   {number} line     The line from the file to use for formatting.
+ * @param   {number} column   The column from the file to use for formatting.
+ * @returns {string}          The formatted file path.
+ */
+function formatFilePath(filePath, line, column) {
+    let relPath = path.relative(process.cwd(), filePath);
+
+    if (line && column) {
+        relPath += `:${line}:${column}`;
+    }
+
+    return chalk.green(relPath);
+}
+
+/**
+ * Gets the formatted output for a given message.
+ * @param   {Object} message      The object that represents this message.
+ * @param   {Object} parentResult The result object that this message belongs to.
+ * @returns {string}              The formatted output.
+ */
+function formatMessage(message, parentResult) {
+    const type = (message.fatal || message.severity === 2) ? chalk.red("error") : chalk.yellow("warning");
+    const msg = `${chalk.bold(message.message.replace(/\.$/, ""))}`;
+    const ruleId = message.fatal ? "" : chalk.dim(`(${message.ruleId})`);
+    const filePath = formatFilePath(parentResult.filePath, message.line, message.column);
+    const sourceCode = parentResult.output ? parentResult.output : parentResult.source;
+
+    const firstLine = [
+        `${type}:`,
+        `${msg}`,
+        ruleId ? `${ruleId}` : "",
+        sourceCode ? `at ${filePath}:` : `at ${filePath}`,
+    ].filter(String).join(" ");
+
+    const result = [ firstLine ];
+
+    if (sourceCode) {
+        result.push(
+            codeFrame(sourceCode, message.line, message.column, { highlightCode: false })
+        );
+    }
+
+    return result.join("\n");
+}
+
+/**
+ * Gets the formatted output summary for a given number of errors and warnings.
+ * @param   {number} errors   The number of errors.
+ * @param   {number} warnings The number of warnings.
+ * @returns {string}          The formatted output summary.
+ */
+function formatSummary(errors, warnings) {
+    const summaryColor = errors > 0 ? "red" : "yellow";
+    const summary = [];
+
+    if (errors > 0) {
+        summary.push(`${errors} ${pluralize("error", errors)}`);
+    }
+
+    if (warnings > 0) {
+        summary.push(`${warnings} ${pluralize("warning", warnings)}`);
+    }
+
+    return chalk[summaryColor].bold(`${summary.join(" and ")} found.`);
+}
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+module.exports = function(results) {
+    let errors = 0;
+    let warnings = 0;
+    const resultsWithMessages = results.filter(result => result.messages.length > 0);
+
+    let output = resultsWithMessages.reduce((resultsOutput, result) => {
+        const messages = result.messages.map(message => {
+            if (message.fatal || message.severity === 2) {
+                errors++;
+            } else {
+                warnings++;
+            }
+
+            return `${formatMessage(message, result)}\n\n`;
+        });
+
+        return resultsOutput.concat(messages);
+    }, []).join("\n");
+
+    output += "\n";
+    output += formatSummary(errors, warnings);
+
+    return (errors + warnings) > 0 ? output : "";
+};