Initial work to add Gatsby remarked plugin to keep headings

gatsby-config.js

@@ -102,6 +102,7 @@ module.exports = {
 							enableCustomId: true
 						}
 					},
+					`remarked-autolink-headers-and-add-id`,
 					{
 						resolve: `gatsby-remark-prismjs`,
 						options: {

package-lock.json

@@ -1281,11 +1281,18 @@
       }
     },
     "@babel/runtime": {
-      "version": "7.3.4",
+      "version": "7.8.4",
-      "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.3.4.tgz",
+      "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.8.4.tgz",
-      "integrity": "sha512-IvfvnMdSaLBateu0jfsYIpZTxAc2cKEXEMiezGGN75QcBcecDUKd3PgLAncT0oOgxKy8dd8hrJKj9MfzgfZd6g==",
+      "integrity": "sha512-neAp3zt80trRVBI1x0azq6c57aNBqYZH8KhMm3TaB7wEI5Q4A2SHfBHE8w9gOhI/lrqxtEbXZgQIrHP+wvSGwQ==",
       "requires": {
-        "regenerator-runtime": "^0.12.0"
+        "regenerator-runtime": "^0.13.2"
+      },
+      "dependencies": {
+        "regenerator-runtime": {
+          "version": "0.13.3",
+          "resolved": "https://registry.npmjs.org/regenerator-runtime/-/regenerator-runtime-0.13.3.tgz",
+          "integrity": "sha512-naKIZz2GQ8JWh///G7L3X6LaQUAMp2lvb1rvwwsURe/VXwD6VMfr+/1NuNw3ag8v2kY1aQ/go5SNn79O9JU7yw=="
+        }
       }
     },
     "@babel/template": {
@@ -20571,9 +20578,9 @@
       }
     },
     "mdast-util-to-string": {
-      "version": "1.0.6",
+      "version": "1.0.7",
-      "resolved": "https://registry.npmjs.org/mdast-util-to-string/-/mdast-util-to-string-1.0.6.tgz",
+      "resolved": "https://registry.npmjs.org/mdast-util-to-string/-/mdast-util-to-string-1.0.7.tgz",
-      "integrity": "sha512-868pp48gUPmZIhfKrLbaDneuzGiw3OTDjHc5M1kAepR2CWBJ+HpEsm252K4aXdiP5coVZaJPOqGtVU6Po8xnXg=="
+      "integrity": "sha512-P+gdtssCoHOX+eJUrrC30Sixqao86ZPlVjR5NEAoy0U79Pfxb1Y0Gntei0+GrnQD4T04X9xA8tcugp90cSmNow=="
     },
     "mdast-util-toc": {
       "version": "2.1.0",
@@ -24091,6 +24098,17 @@
         "prop-types": "15.7.2",
         "react-fast-compare": "2.0.4",
         "shallowequal": "1.1.0"
+      },
+      "dependencies": {
+        "@babel/runtime": {
+          "version": "7.3.4",
+          "resolved": "https://registry.npmjs.org/@babel/runtime/-/runtime-7.3.4.tgz",
+          "integrity": "sha512-IvfvnMdSaLBateu0jfsYIpZTxAc2cKEXEMiezGGN75QcBcecDUKd3PgLAncT0oOgxKy8dd8hrJKj9MfzgfZd6g==",
+          "dev": true,
+          "requires": {
+            "regenerator-runtime": "^0.12.0"
+          }
+        }
       }
     },
     "react-hot-loader": {
@@ -24556,7 +24574,8 @@
     "regenerator-runtime": {
       "version": "0.12.1",
       "resolved": "https://registry.npmjs.org/regenerator-runtime/-/regenerator-runtime-0.12.1.tgz",
-      "integrity": "sha512-odxIc1/vDlo4iZcfXqRYFj0vpXFNoGdKMAUieAlFYO6m/nl5e9KR/beGf41z4a1FI+aQgtjhuaSlDxQ0hmkrHg=="
+      "integrity": "sha512-odxIc1/vDlo4iZcfXqRYFj0vpXFNoGdKMAUieAlFYO6m/nl5e9KR/beGf41z4a1FI+aQgtjhuaSlDxQ0hmkrHg==",
+      "dev": true
     },
     "regenerator-transform": {
       "version": "0.14.0",
@@ -28437,6 +28456,21 @@
         "unist-util-is": "^3.0.0"
       }
     },
+    "unist-util-flat-filter": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/unist-util-flat-filter/-/unist-util-flat-filter-1.0.0.tgz",
+      "integrity": "sha512-zjTmbMgyL1V7iUCnFaGLms9HtGbqK4d3YINqzu+wiMbau93GdiDGtJiB8lMhAyxAaxIAK2rOCeBCldF0FUreKQ==",
+      "requires": {
+        "unist-util-is": "^4.0.0"
+      },
+      "dependencies": {
+        "unist-util-is": {
+          "version": "4.0.1",
+          "resolved": "https://registry.npmjs.org/unist-util-is/-/unist-util-is-4.0.1.tgz",
+          "integrity": "sha512-7NYjErP4LJtkEptPR22wO5RsCPnHZZrop7t2SoQzjvpFedCFer4WW8ujj9GI5DkUX7yVcffXLjoURf6h2QUv6Q=="
+        }
+      }
+    },
     "unist-util-generated": {
       "version": "1.1.4",
       "resolved": "https://registry.npmjs.org/unist-util-generated/-/unist-util-generated-1.1.4.tgz",

package.json

@@ -61,7 +61,7 @@
     "react-helmet": "^5.2.1",
     "react-paginate": "^6.3.0",
     "react-pose": "^4.0.9",
-    "unist-util-visit": "^1.4.1"
+    "unist-util-flat-filter": "^1.0.0"
   },
   "peerDependencies": {
     "@reach/router": "^1.1.1"
@@ -106,6 +106,7 @@
   },
   "scripts": {
     "build": "gatsby build",
+    "debug": "gatsby clean && node --nolazy --inspect-brk ./node_modules/.bin/gatsby develop",
     "develop": "gatsby develop",
     "format": "run-s format:**",
     "format:js": "eslint --fix ./src",

plugins/remarked-autolink-headers-and-add-id/index.js

@@ -0,0 +1,26 @@
+const flatFilter = require("unist-util-flat-filter");
+
+module.exports = ({ markdownAST, actions, markdownNode }) => {
+	const { createNodeField } = actions;
+
+	const values = flatFilter(markdownAST, node => node.type === "heading");
+
+	const headings = values.children.map(node => {
+		const last = node.children[node.children.length - 1];
+
+		return {
+			value: last.value,
+			depth: node.depth,
+			// This is added by the `gatsby-remark-autolink-headers` plugin, we're just using it here
+			// This means that it must come after that plugin in your config file
+			slug: node.data.id
+		};
+	});
+
+	createNodeField({
+		name: `headingsWithId`,
+		node: markdownNode,
+		value: headings
+	});
+	return markdownAST;
+};

plugins/remarked-autolink-headers-and-add-id/package.json

@@ -0,0 +1,46 @@
+{
+  "name": "remarked-autolink-headers-and-add-id",
+  "description": "Gatsby plugin to autolink headers in markdown processed by Remark",
+  "version": "2.1.24",
+  "author": "Kyle Mathews <mathews.kyle@gmail.com>",
+  "bugs": {
+    "url": "https://github.com/gatsbyjs/gatsby/issues"
+  },
+  "dependencies": {
+    "@babel/runtime": "^7.7.6",
+    "github-slugger": "^1.2.1",
+    "lodash": "^4.17.15",
+    "mdast-util-to-string": "^1.0.7",
+    "unist-util-visit": "^1.4.1",
+    "unist-util-flatmap": "^1.0.0"
+  },
+  "devDependencies": {
+    "@babel/cli": "^7.7.5",
+    "@babel/core": "^7.7.5",
+    "babel-preset-gatsby-package": "^0.2.16",
+    "cross-env": "^5.2.1"
+  },
+  "homepage": "https://github.com/gatsbyjs/gatsby/tree/master/packages/gatsby-remark-autolink-headers#readme",
+  "keywords": [
+    "gatsby",
+    "gatsby-plugin",
+    "remark"
+  ],
+  "license": "MIT",
+  "main": "index.js",
+  "peerDependencies": {
+    "gatsby": "^2.0.0"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/gatsbyjs/gatsby.git",
+    "directory": "packages/gatsby-remark-autolink-headers"
+  },
+  "scripts": {
+    "build": "babel src --out-dir . --ignore **/__tests__",
+    "watch": "babel -w src --out-dir . --ignore **/__tests__"
+  },
+  "engines": {
+    "node": ">=8.0.0"
+  }
+}