Add support for input from stdin via "-" glob (fixes #414).

README.md

@@ -76,6 +76,7 @@ Glob expressions (from the globby library):
 - {} allows for a comma-separated list of "or" expressions
 - ! or # at the beginning of a pattern negate the match
 - : at the beginning identifies a literal file path
+- - as a glob represents standard input (stdin)
 
 Dot-only glob:
 - The command "markdownlint-cli2 ." would lint every file in the current directory tree which is probably not intended

markdownlint-cli2.js

@@ -263,6 +263,7 @@ Glob expressions (from the globby library):
 - {} allows for a comma-separated list of "or" expressions
 - ! or # at the beginning of a pattern negate the match
 - : at the beginning identifies a literal file path
+- - as a glob represents standard input (stdin)
 
 Dot-only glob:
 - The command "markdownlint-cli2 ." would lint every file in the current directory tree which is probably not intended
@@ -807,7 +808,8 @@ const lintFiles = (fs, dirInfos, fileContents) => {
       task = task.then((results) => {
         options.files = [];
         const subTasks = [];
-        const errorFiles = Object.keys(results);
+        const errorFiles = Object.keys(results).
+          filter((result) => filteredFiles.includes(result));
         for (const fileName of errorFiles) {
           const errorInfos = results[fileName].
             filter((errorInfo) => errorInfo.fixInfo);
@@ -909,11 +911,12 @@ const main = async (params) => {
     optionsDefault,
     optionsOverride,
     fileContents,
-    nonFileContents,
-    noRequire
+    noRequire,
+    allowStdin
   } = params;
   let {
-    noGlobs
+    noGlobs,
+    nonFileContents
   } = params;
   const logMessage = params.logMessage || noop;
   const logError = params.logError || noop;
@@ -926,13 +929,16 @@ const main = async (params) => {
   let fixDefault = false;
   // eslint-disable-next-line unicorn/no-useless-undefined
   let configPath = undefined;
+  let useStdin = false;
   let sawDashDash = false;
   let shouldShowHelp = false;
   const argvFiltered = (argv || []).filter((arg) => {
     if (sawDashDash) {
       return true;
     } else if (configPath === null) {
       configPath = arg;
+    } else if ((arg === "-") && allowStdin) {
+      useStdin = true;
       // eslint-disable-next-line unicorn/prefer-switch
     } else if (arg === "--") {
       sawDashDash = true;
@@ -983,22 +989,30 @@ const main = async (params) => {
     }
   }
   if (
-    ((globPatterns.length === 0) && !nonFileContents) ||
+    ((globPatterns.length === 0) && !useStdin && !nonFileContents) ||
     (configPath === null)
   ) {
     return showHelp(logMessage, false);
   }
+  // Add stdin as a non-file input if necessary
+  if (useStdin) {
+    const key = pathPosix.join(baseDir, "stdin");
+    const { text } = require("node:stream/consumers");
+    nonFileContents = {
+      ...nonFileContents,
+      [key]: await text(process.stdin)
+    };
+  }
   // Include any file overrides or non-file content
-  const { baseMarkdownlintOptions, dirToDirInfo } = baseOptions;
   const resolvedFileContents = {};
   for (const file in fileContents) {
     const resolvedFile = posixPath(pathDefault.resolve(baseDirSystem, file));
-    resolvedFileContents[resolvedFile] =
-      fileContents[file];
+    resolvedFileContents[resolvedFile] = fileContents[file];
   }
   for (const nonFile in nonFileContents) {
     resolvedFileContents[nonFile] = nonFileContents[nonFile];
   }
+  const { baseMarkdownlintOptions, dirToDirInfo } = baseOptions;
   appendToArray(
     dirToDirInfo[baseDir].files,
     Object.keys(nonFileContents || {})
@@ -1079,7 +1093,8 @@ const run = (overrides, args) => {
       const defaultParams = {
         "argv": argsAndArgv,
         "logMessage": console.log,
-        "logError": console.error
+        "logError": console.error,
+        "allowStdin": true
       };
       const params = {
         ...defaultParams,

test/markdownlint-cli2-test-exec.js

@@ -4,15 +4,19 @@
 
 const fs = require("node:fs/promises");
 const path = require("node:path");
+const test = require("ava").default;
 const testCases = require("./markdownlint-cli2-test-cases");
 
+const absolute = (rootDir, file) => path.join(rootDir, file);
+const repositoryPath = (name) => path.join(__dirname, "..", name);
+
 const invoke = (directory, args, noRequire, env, script) => async () => {
   await fs.access(directory);
   const { "default": spawn } = await import("nano-spawn");
   return spawn(
     "node",
     [
-      path.join(__dirname, "..", script || "markdownlint-cli2.js"),
+      repositoryPath(script || "markdownlint-cli2.js"),
       ...args
     ],
     {
@@ -27,8 +31,6 @@ const invoke = (directory, args, noRequire, env, script) => async () => {
     catch((error) => error);
 };
 
-const absolute = (rootDir, file) => path.join(rootDir, file);
-
 testCases({
   "host": "exec",
   invoke,
@@ -39,3 +41,151 @@ testCases({
   "includeRequire": true,
   "includeAbsolute": true
 });
+
+const invokeStdin = async (args, stdin, cwd) => {
+  const { "default": spawn } = await import("nano-spawn");
+  return spawn(
+    "node",
+    [
+      repositoryPath("markdownlint-cli2.js"),
+      ...args
+    ],
+    {
+      cwd,
+      "stdin": { "string": stdin }
+    }
+  );
+};
+
+const validInput = "# Heading\n\nText\n";
+const invalidInput = "#  Heading\n\nText";
+
+test("- parameter with empty input from stdin", (t) => {
+  t.plan(1);
+  return invokeStdin(
+    [ "-" ],
+    ""
+  ).
+    then(() => t.pass()).
+    catch(() => t.fail());
+});
+
+test("- parameter with valid input from stdin", (t) => {
+  t.plan(1);
+  return invokeStdin(
+    [ "-" ],
+    validInput
+  ).
+    then(() => t.pass()).
+    catch(() => t.fail());
+});
+
+test("- parameter with invalid input from stdin", (t) => {
+  t.plan(2);
+  return invokeStdin(
+    [ "-" ],
+    invalidInput
+  ).
+    then(() => t.fail()).
+    catch((error) => {
+      t.is(error.exitCode, 1);
+      t.is("", error.stderr.replace(/^stdin:1:3 MD019\/.*$[\n\r]+^stdin:3:4 MD047\/.*$/mu, ""));
+    });
+});
+
+test("- parameter with invalid input from stdin and --fix", (t) => {
+  t.plan(2);
+  return invokeStdin(
+    [ "-", "--fix" ],
+    invalidInput
+  ).
+    then(() => t.fail()).
+    catch((error) => {
+      t.is(error.exitCode, 1);
+      t.is("", error.stderr.replace(/^stdin:1:3 MD019\/.*$[\n\r]+^stdin:3:4 MD047\/.*$/mu, ""));
+    });
+});
+
+test("- parameter multiple times with invalid input", (t) => {
+  t.plan(2);
+  return invokeStdin(
+    [ "-", "-" ],
+    invalidInput
+  ).
+    then(() => t.fail()).
+    catch((error) => {
+      t.is(error.exitCode, 1);
+      t.is("", error.stderr.replace(/^stdin:1:3 MD019\/.*$[\n\r]+^stdin:3:4 MD047\/.*$/mu, ""));
+    });
+});
+
+test("- parameter with valid input combined with valid globs", (t) => {
+  t.plan(1);
+  return invokeStdin(
+    [ repositoryPath("CONTRIBUTING.md"), "-", repositoryPath("README.md") ],
+    validInput
+  ).
+    then(() => t.pass()).
+    catch(() => t.fail());
+});
+
+test("- parameter with invalid input combined with valid globs", (t) => {
+  t.plan(2);
+  return invokeStdin(
+    [ repositoryPath("CONTRIBUTING.md"), repositoryPath("README.md"), "-" ],
+    invalidInput
+  ).
+    then(() => t.fail()).
+    catch((error) => {
+      t.is(error.exitCode, 1);
+      t.is("", error.stderr.replace(/^stdin:1:3 MD019\/.*$[\n\r]+^stdin:3:4 MD047\/.*$/mu, ""));
+    });
+});
+
+test("- parameter with invalid input combined with invalid glob", (t) => {
+  t.plan(2);
+  return invokeStdin(
+    [ "-", repositoryPath("LICENSE") ],
+    invalidInput
+  ).
+    then(() => t.fail()).
+    catch((error) => {
+      t.is(error.exitCode, 1);
+      t.is("", error.stderr.replace(/^LICENSE:1 MD041\/.*$[\n\r]+^stdin:1:3 MD019\/.*$[\n\r]+^stdin:3:4 MD047\/.*$/mu, ""));
+    });
+});
+
+test("- parameter uses base directory configuration", (t) => {
+  t.plan(2);
+  return invokeStdin(
+    [ "-" ],
+    invalidInput,
+    path.join(__dirname, "stdin")
+  ).
+    then(() => t.fail()).
+    catch((error) => {
+      t.is(error.exitCode, 1);
+      t.is("", error.stderr.replace(/^stdin:1:3 MD019\/.*$/mu, ""));
+    });
+});
+
+test("- parameter not treated as stdin in configuration file globs", (t) => {
+  t.plan(1);
+  return invokeStdin(
+    [],
+    invalidInput,
+    path.join(__dirname, "stdin-globs")
+  ).
+    then(() => t.pass()).
+    catch(() => t.fail());
+});
+
+test("- parameter ignored after --", (t) => {
+  t.plan(1);
+  return invokeStdin(
+    [ "--", "-" ],
+    invalidInput
+  ).
+    then(() => t.pass()).
+    catch(() => t.fail());
+});

test/markdownlint-cli2-test.js

@@ -67,7 +67,7 @@ test("README files", (t) => {
 });
 
 test("validateMarkdownlintConfigSchema", async (t) => {
-  t.plan(26);
+  t.plan(27);
 
   // Validate schema
   // @ts-ignore
@@ -111,7 +111,7 @@ test("validateMarkdownlintConfigSchema", async (t) => {
 });
 
 test("validateMarkdownlintCli2ConfigSchema", async (t) => {
-  t.plan(90);
+  t.plan(91);
 
   // Validate schema
   // @ts-ignore
@@ -696,3 +696,16 @@ test("-- stops matching parameters per POSIX Utility Conventions 12.2 Guideline
   files.push([ "/--", "# Title" ]);
   await scenario([ "--", "--" ], 1);
 });
+
+test ("- not supported by main entry point", (t) => {
+  t.plan(2);
+  return markdownlintCli2({
+    "argv": [ "-" ],
+    "optionsOverride": {
+      "outputFormatters": [ [ outputFormatterLengthIs(t, 0) ] ]
+    }
+  }).
+    then((exitCode) => {
+      t.is(exitCode, 0);
+    });
+});

test/snapshots/markdownlint-cli2-test-exec.js.md

@@ -27,6 +27,7 @@ Generated by [AVA](https://avajs.dev).
       - {} allows for a comma-separated list of "or" expressions␊
       - ! or # at the beginning of a pattern negate the match␊
       - : at the beginning identifies a literal file path␊
+      - - as a glob represents standard input (stdin)␊
       ␊
       Dot-only glob:␊
       - The command "markdownlint-cli2 ." would lint every file in the current directory tree which is probably not intended␊
@@ -83,6 +84,7 @@ Generated by [AVA](https://avajs.dev).
       - {} allows for a comma-separated list of "or" expressions␊
       - ! or # at the beginning of a pattern negate the match␊
       - : at the beginning identifies a literal file path␊
+      - - as a glob represents standard input (stdin)␊
       ␊
       Dot-only glob:␊
       - The command "markdownlint-cli2 ." would lint every file in the current directory tree which is probably not intended␊
@@ -139,6 +141,7 @@ Generated by [AVA](https://avajs.dev).
       - {} allows for a comma-separated list of "or" expressions␊
       - ! or # at the beginning of a pattern negate the match␊
       - : at the beginning identifies a literal file path␊
+      - - as a glob represents standard input (stdin)␊
       ␊
       Dot-only glob:␊
       - The command "markdownlint-cli2 ." would lint every file in the current directory tree which is probably not intended␊
@@ -195,6 +198,7 @@ Generated by [AVA](https://avajs.dev).
       - {} allows for a comma-separated list of "or" expressions␊
       - ! or # at the beginning of a pattern negate the match␊
       - : at the beginning identifies a literal file path␊
+      - - as a glob represents standard input (stdin)␊
       ␊
       Dot-only glob:␊
       - The command "markdownlint-cli2 ." would lint every file in the current directory tree which is probably not intended␊
@@ -681,6 +685,7 @@ Generated by [AVA](https://avajs.dev).
       - {} allows for a comma-separated list of "or" expressions␊
       - ! or # at the beginning of a pattern negate the match␊
       - : at the beginning identifies a literal file path␊
+      - - as a glob represents standard input (stdin)␊
       ␊
       Dot-only glob:␊
       - The command "markdownlint-cli2 ." would lint every file in the current directory tree which is probably not intended␊