Refactor new MD054/link-image-style rule, add tests, update documentation (fixes #40, fixes #399).

lib/md054.js

@@ -2,92 +2,23 @@
 
 "use strict";
 
-const { addErrorContext } = require("../helpers");
+const { addErrorContext, nextLinesRe } = require("../helpers");
 const { filterByTypes, filterByPredicate, getTokenTextByType } =
   require("../helpers/micromark.cjs");
+const { referenceLinkImageData } = require("./cache");
 
-const isInlineLink = ({ children }) => children.some(
-  ({ type }) => type === "resource"
-);
-
-const isAutolink = ({ type }) => type === "autolink";
-
-const getNestedTokenTextByType = (tokens, type) => getTokenTextByType(
-  filterByTypes(tokens, [ type ]),
-  type
-);
-
-const escapeParentheses = (unescaped) => unescaped
-  .replaceAll("(", "\\(")
-  .replaceAll(")", "\\)");
-const escapeSquares = (unescaped) => unescaped
-  .replaceAll("[", "\\[")
-  .replaceAll("]", "\\]");
-const escapeAngles = (unescaped) => unescaped
-  .replaceAll("<", "\\<")
-  .replaceAll(">", "\\>");
-
-const unescapeParentheses = (escaped) => escaped
-  .replaceAll("\\(", "(")
-  .replaceAll("\\)", ")");
-const unescapeAngles = (escaped) => escaped
-  .replaceAll("\\<", "<")
-  .replaceAll("\\>", ">");
-
-const referenceLinkDestination = (link, tokens) => {
-  const reference = getNestedTokenTextByType([ link ], "reference");
-  const id = reference && reference !== "[]" ?
-    reference.replace(/^\[/, "").replace(/\]$/, "") :
-    getNestedTokenTextByType([ link ], "labelText");
-
-  const definition = filterByPredicate(
-    filterByTypes(tokens, [ "definition" ]),
-    (d) => getNestedTokenTextByType([ d ], "definitionLabelString") === id
-  );
-  return getNestedTokenTextByType(definition, "definitionDestination");
-};
-
-const inlineLinkDestination = (link) => {
-  const text = getNestedTokenTextByType([ link ], "resourceDestination");
-  return text && unescapeParentheses(text);
-};
-
-const autolinkDestination = (link) => {
-  const text = getNestedTokenTextByType([ link ], "autolinkProtocol");
-  return text && unescapeAngles(text);
-};
-
-const autolinkFixInfo = (tokens, link) => {
-  if (isAutolink(link)) {
-    return null;
+const backslashEscapeRe = /\\([!"#$%&'()*+,\-./:;<=>?@[\\\]^_`{|}~])/g;
+const removeBackslashEscapes = (text) => text.replace(backslashEscapeRe, "$1");
+const autolinkDisallowedRe = /[ <>]/;
+const autolinkAble = (destination) => {
+  try {
+    // eslint-disable-next-line no-new
+    new URL(destination);
+  } catch {
+    // Not an absolute URL
+    return false;
   }
-
-  const destination = isInlineLink(link) ?
-    inlineLinkDestination(link) :
-    referenceLinkDestination(link, tokens);
-
-  return {
-    "editColumn": link.startColumn,
-    "insertText": `<${escapeAngles(destination)}>`,
-    "deleteCount": link.endColumn - link.startColumn
-  };
-};
-
-const inlineFixInfo = (tokens, link) => {
-  if (isInlineLink(link)) {
-    return null;
-  }
-
-  const destination = isAutolink(link) ?
-    autolinkDestination(link) :
-    referenceLinkDestination(link, tokens);
-
-  return {
-    "editColumn": link.startColumn,
-    "insertText":
-      `[${escapeSquares(destination)}](${escapeParentheses(destination)})`,
-    "deleteCount": link.endColumn - link.startColumn
-  };
+  return !autolinkDisallowedRe.test(destination);
 };
 
 module.exports = {
@@ -95,34 +26,77 @@ module.exports = {
   "description": "Link and image style",
   "tags": [ "images", "links" ],
   "function": ({ parsers, config }, onError) => {
-    const style = String(config.style || "mixed");
+    const autolink = (config.autolink === undefined) || !!config.autolink;
+    const inline = (config.inline === undefined) || !!config.inline;
+    const reference = (config.reference === undefined) || !!config.reference;
+    if (autolink && inline && reference) {
+      // Everything allowed, nothing to check
+      return;
+    }
+    const { definitions } = referenceLinkImageData();
     const links = filterByTypes(
       parsers.micromark.tokens,
-      [ "autolink", "link", "image" ]
+      [ "autolink", "image", "link" ]
     );
     for (const link of links) {
-      const inlineLink = isInlineLink(link);
-      const autolink = isAutolink(link);
-
-      const range = [ link.startColumn, link.endColumn - link.startColumn ];
-      let fixInfo = null;
-      if (style === "autolink_only") {
-        fixInfo = autolinkFixInfo(parsers.micromark.tokens, link);
-      } else if (style === "inline_only") {
-        fixInfo = inlineFixInfo(parsers.micromark.tokens, link);
+      let label = null;
+      let destination = null;
+      const {
+        children, endColumn, endLine, startColumn, startLine, text, type
+      } = link;
+      const image = (type === "image");
+      let isError = false;
+      if (type === "autolink") {
+        // link kind is an autolink
+        destination = getTokenTextByType(children, "autolinkProtocol");
+        label = destination;
+        isError = !autolink;
+      } else {
+        // link type is "image" or "link"
+        const descendents = filterByPredicate(children);
+        label = getTokenTextByType(descendents, "labelText");
+        destination =
+          getTokenTextByType(descendents, "resourceDestinationString");
+        if (destination) {
+          // link kind is an inline link
+          isError = !inline;
+        } else {
+          // link kind is a reference link
+          const referenceLabel =
+            getTokenTextByType(descendents, "referenceString") || label;
+          const definition = definitions.get(referenceLabel);
+          destination = definition && definition[1];
+          isError = !reference && destination;
+        }
       }
-
-      if (
-        fixInfo ||
-        (style === "reference_only" && (inlineLink || autolink)) ||
-        (style === "inline_or_reference" && autolink) ||
-        (style === "inline_or_autolink" && !(inlineLink || autolink)) ||
-        (style === "reference_or_autolink" && inlineLink)
-      ) {
+      if (isError) {
+        let range = null;
+        let fixInfo = null;
+        if (startLine === endLine) {
+          range = [ startColumn, endColumn - startColumn ];
+          let insertText = null;
+          if (inline && label) {
+            // Most useful form
+            const prefix = (image ? "!" : "");
+            const escapedLabel = label.replace(/[[\]]/g, "\\$&");
+            const escapedDestination = destination.replace(/[()]/g, "\\$&");
+            insertText = `${prefix}[${escapedLabel}](${escapedDestination})`;
+          } else if (autolink && !image && autolinkAble(destination)) {
+            // Simplest form
+            insertText = `<${removeBackslashEscapes(destination)}>`;
+          }
+          if (insertText) {
+            fixInfo = {
+              "editColumn": range[0],
+              insertText,
+              "deleteCount": range[1]
+            };
+          }
+        }
         addErrorContext(
           onError,
-          link.startLine,
-          link.text,
+          startLine,
+          text.replace(nextLinesRe, ""),
           null,
           null,
           range,