--- /dev/null
+"use strict";
+
+const _ = require("lodash");
+const assignDisabledRanges = require("../assignDisabledRanges");
+const basicChecks = require("./basicChecks");
+const lessSyntax = require("postcss-less");
+const normalizeRuleSettings = require("../normalizeRuleSettings");
+const postcss = require("postcss");
+const scssSyntax = require("postcss-scss");
+const sugarss = require("sugarss");
+
+/**
+ * Create a stylelint rule testing function.
+ *
+ * Pass in an `equalityCheck` function. Given some information,
+ * this checker should use Whatever Test Runner to perform
+ * equality checks.
+ *
+ * `equalityCheck` should accept two arguments:
+ * - `processCss` {Promise}: A Promise that resolves with an array of
+ * comparisons that you need to check (documented below).
+ * - `context` {object}: An object that contains additional information
+ * you may need:
+ * - `caseDescription` {string}: A description of the test case as a whole.
+ * Will look like this:
+ * > rule: value-list-comma-space-before
+ * > config: "always-single-line"
+ * > code: "a { background-size: 0 ,0;\n}"
+ * - `comparisonCount` {number}: The number of comparisons that
+ * will need to be performed (e.g. useful for tape).
+ * - `completeAssertionDescription` {string}: While each individual
+ * comparison may have its own description, this is a description
+ * of the whole assertion (e.g. useful for Mocha).
+ * - `only` {boolean}: If `true`, the test runner should only run this
+ * test case (e.g. `test.only` in tape, `describe.only` in Mocha).
+ *
+ * `processCss` is a Promsie that resolves with an array of comparisons.
+ * Each comparison has the following properties:
+ * - `actual` {any}: Some actual value.
+ * - `expected` {any}: Some expected value.
+ * - `description` {string}: A (possibly empty) description of the comparison.
+ *
+ * Within `equalityCheck`, you need to ensure that you:
+ * - Set up the test case.
+ * - When `processCss` resolves, loop through every comparison.
+ * - For each comparison, make an assertion checking that `actual === expected`.
+ *
+ * The `testRule` function that you get has a simple signature:
+ * `testRule(rule, testGroupDescription)`.
+ *
+ * `rule` is just the rule that you are testing (a function).
+ *
+ * `testGroupDescription` is an object fitting the following schema.
+ *
+ * Required properties:
+ * - `ruleName` {string}: The name of the rule. Used in descriptions.
+ * - `config` {any}: The rule's configuration for this test group.
+ * Should match the format you'd use in `.stylelintrc`.
+ * - `accept` {array}: An array of objects describing test cases that
+ * should not violate the rule. Each object has these properties:
+ * - `code` {string}: The source CSS to check.
+ * - `description` {[string]}: An optional description of the case.
+ * - `reject` {array}: An array of objects describing test cases that
+ * should violate the rule once. Each object has these properties:
+ * - `code` {string}: The source CSS to check.
+ * - `message` {string}: The message of the expected violation.
+ * - `line` {[number]}: The expected line number of the violation.
+ * If this is left out, the line won't be checked.
+ * - `column` {[number]}: The expected column number of the violation.
+ * If this is left out, the column won't be checked.
+ * - `description` {[string]}: An optional description of the case.
+ *
+ * Optional properties:
+ * - `syntax` {"css"|"scss"|"less"|"sugarss"}: Defaults to `"css"`.
+ * - `skipBasicChecks` {boolean}: Defaults to `false`. If `true`, a
+ * few rudimentary checks (that should almost always be included)
+ * will not be performed.
+ * - `preceedingPlugins` {array}: An array of PostCSS plugins that
+ * should be run before the CSS is tested.
+ *
+ * @param {function} equalityCheck - Described above
+ * @return {function} testRule - Decsribed above
+ */
+let onlyTest;
+
+function checkCaseForOnly(caseType, testCase) {
+ if (!testCase.only) {
+ return;
+ }
+ /* istanbul ignore next */
+ if (onlyTest) {
+ throw new Error("Cannot use `only` on multiple test cases");
+ }
+ onlyTest = { case: testCase, type: caseType };
+}
+
+module.exports = function(equalityCheck) {
+ return function(rule, schema) {
+ const alreadyHadOnlyTest = !!onlyTest;
+ if (schema.accept) {
+ schema.accept.forEach(_.partial(checkCaseForOnly, "accept"));
+ }
+
+ if (schema.reject) {
+ schema.reject.forEach(_.partial(checkCaseForOnly, "reject"));
+ }
+
+ if (onlyTest) {
+ schema = _.assign(_.omit(schema, ["accept", "reject"]), {
+ skipBasicChecks: true,
+ [onlyTest.type]: [onlyTest.case]
+ });
+ }
+
+ if (!alreadyHadOnlyTest) {
+ process.nextTick(() => {
+ processGroup(rule, schema, equalityCheck);
+ });
+ }
+ };
+};
+
+function processGroup(rule, schema, equalityCheck) {
+ const ruleName = schema.ruleName;
+
+ const ruleOptions = normalizeRuleSettings(schema.config, ruleName);
+ const rulePrimaryOptions = ruleOptions[0];
+ const ruleSecondaryOptions = ruleOptions[1];
+
+ let printableConfig = rulePrimaryOptions
+ ? JSON.stringify(rulePrimaryOptions)
+ : "";
+ if (printableConfig && ruleSecondaryOptions) {
+ printableConfig += ", " + JSON.stringify(ruleSecondaryOptions);
+ }
+
+ function createCaseDescription(code) {
+ let text = `\n> rule: ${ruleName}\n`;
+ text += `> config: ${printableConfig}\n`;
+ text += `> code: ${JSON.stringify(code)}\n`;
+ return text;
+ }
+
+ // Process the code through the rule and return
+ // the PostCSS LazyResult promise
+ function postcssProcess(code) {
+ const postcssProcessOptions = {};
+
+ switch (schema.syntax) {
+ case "scss":
+ postcssProcessOptions.syntax = scssSyntax;
+ break;
+ case "less":
+ postcssProcessOptions.syntax = lessSyntax;
+ break;
+ case "sugarss":
+ postcssProcessOptions.syntax = sugarss;
+ break;
+ }
+
+ const processor = postcss();
+ processor.use(assignDisabledRanges);
+
+ if (schema.preceedingPlugins) {
+ schema.preceedingPlugins.forEach(plugin => processor.use(plugin));
+ }
+
+ return processor
+ .use(rule(rulePrimaryOptions, ruleSecondaryOptions))
+ .process(code, postcssProcessOptions);
+ }
+
+ // Apply the basic positive checks unless
+ // explicitly told not to
+ const passingTestCases = schema.skipBasicChecks
+ ? schema.accept
+ : basicChecks.concat(schema.accept);
+
+ if (passingTestCases && passingTestCases.length) {
+ passingTestCases.forEach(acceptedCase => {
+ if (!acceptedCase) {
+ return;
+ }
+ const assertionDescription = spaceJoin(
+ acceptedCase.description,
+ "should be accepted"
+ );
+ const resultPromise = postcssProcess(acceptedCase.code)
+ .then(postcssResult => {
+ const warnings = postcssResult.warnings();
+ return [
+ {
+ expected: 0,
+ actual: warnings.length,
+ description: assertionDescription
+ }
+ ];
+ })
+ .catch(err => console.log(err.stack)); // eslint-disable-line no-console
+
+ equalityCheck(resultPromise, {
+ comparisonCount: 1,
+ caseDescription: createCaseDescription(acceptedCase.code),
+ completeAssertionDescription: assertionDescription
+ });
+ });
+ }
+
+ if (schema.reject && schema.reject.length) {
+ schema.reject.forEach(rejectedCase => {
+ let completeAssertionDescription = "should register one warning";
+ let comparisonCount = 1;
+ if (rejectedCase.line) {
+ comparisonCount++;
+ completeAssertionDescription += ` on line ${rejectedCase.line}`;
+ }
+ if (rejectedCase.column !== undefined) {
+ comparisonCount++;
+ completeAssertionDescription += ` on column ${rejectedCase.column}`;
+ }
+ if (rejectedCase.message) {
+ comparisonCount++;
+ completeAssertionDescription += ` with message "${
+ rejectedCase.message
+ }"`;
+ }
+
+ const resultPromise = postcssProcess(rejectedCase.code)
+ .then(postcssResult => {
+ const warnings = postcssResult.warnings();
+ const warning = warnings[0];
+
+ const comparisons = [
+ {
+ expected: 1,
+ actual: warnings.length,
+ description: spaceJoin(
+ rejectedCase.description,
+ "should register one warning"
+ )
+ }
+ ];
+
+ if (rejectedCase.line) {
+ comparisons.push({
+ expected: rejectedCase.line,
+ actual: _.get(warning, "line"),
+ description: spaceJoin(
+ rejectedCase.description,
+ `should warn on line ${rejectedCase.line}`
+ )
+ });
+ }
+ if (rejectedCase.column !== undefined) {
+ comparisons.push({
+ expected: rejectedCase.column,
+ actual: _.get(warning, "column"),
+ description: spaceJoin(
+ rejectedCase.description,
+ `should warn on column ${rejectedCase.column}`
+ )
+ });
+ }
+ if (rejectedCase.message) {
+ comparisons.push({
+ expected: rejectedCase.message,
+ actual: _.get(warning, "text"),
+ description: spaceJoin(
+ rejectedCase.description,
+ `should warn with message ${rejectedCase.message}`
+ )
+ });
+ }
+ return comparisons;
+ })
+ .catch(err => console.log(err.stack)); // eslint-disable-line no-console
+
+ equalityCheck(resultPromise, {
+ comparisonCount,
+ completeAssertionDescription,
+ caseDescription: createCaseDescription(rejectedCase.code),
+ only: rejectedCase.only
+ });
+ });
+ }
+}
+
+function spaceJoin() {
+ return _.compact(Array.from(arguments)).join(" ");
+}