From da0d4da4d5a39c865dd68d78a14ee3533adcb943 Mon Sep 17 00:00:00 2001
From: Maxime Thirouin <m@moox.io>
Date: Wed, 2 May 2018 21:55:57 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=94=A5=20Add=20a=20new=20helper=20to=20ex?=
 =?UTF-8?q?tract=20meta=20from=20body=20nodes=20(title=20+=20headers=20lis?=
 =?UTF-8?q?t)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../extractMetaFromBodyNode.js.snap           |  25 ++++
 .../src/__tests__/extractMetaFromBodyNode.js  | 117 ++++++++++++++++++
 .../src/extractMetaFromBodyNode.js            |  43 +++++++
 3 files changed, 185 insertions(+)
 create mode 100644 packages/helpers-transform/src/__tests__/__snapshots__/extractMetaFromBodyNode.js.snap
 create mode 100644 packages/helpers-transform/src/__tests__/extractMetaFromBodyNode.js
 create mode 100644 packages/helpers-transform/src/extractMetaFromBodyNode.js

diff --git a/packages/helpers-transform/src/__tests__/__snapshots__/extractMetaFromBodyNode.js.snap b/packages/helpers-transform/src/__tests__/__snapshots__/extractMetaFromBodyNode.js.snap
new file mode 100644
index 000000000..010db2eba
--- /dev/null
+++ b/packages/helpers-transform/src/__tests__/__snapshots__/extractMetaFromBodyNode.js.snap
@@ -0,0 +1,25 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`should guess partial data from body AST 1`] = `
+Object {
+  "headers": Array [
+    Array [
+      1,
+      "Auto title",
+    ],
+    Array [
+      2,
+      "Sub title",
+    ],
+    Array [
+      2,
+      "Another Level 2",
+    ],
+    Array [
+      3,
+      "A level 3",
+    ],
+  ],
+  "title": "Auto title",
+}
+`;
diff --git a/packages/helpers-transform/src/__tests__/extractMetaFromBodyNode.js b/packages/helpers-transform/src/__tests__/extractMetaFromBodyNode.js
new file mode 100644
index 000000000..b78e65491
--- /dev/null
+++ b/packages/helpers-transform/src/__tests__/extractMetaFromBodyNode.js
@@ -0,0 +1,117 @@
+// @flow
+
+import extractMetaFromBodyNode from "../extractMetaFromBodyNode.js";
+
+it("should guess partial data from body AST", () => {
+  expect(
+    extractMetaFromBodyNode({
+      c: [
+        {
+          c: [
+            {
+              c: [
+                {
+                  p: {
+                    className: "icon icon-link"
+                  },
+                  t: "span"
+                }
+              ],
+              p: {
+                "aria-hidden": true,
+                href: "#auto-title"
+              },
+              t: "a"
+            },
+            "Auto title"
+          ],
+          p: {
+            id: "auto-title"
+          },
+          t: "h1"
+        },
+        "\n",
+        {
+          c: [
+            {
+              c: [
+                {
+                  p: {
+                    className: "icon icon-link"
+                  },
+                  t: "span"
+                }
+              ],
+              p: {
+                "aria-hidden": true,
+                href: "#sub-title"
+              },
+              t: "a"
+            },
+            "Sub title"
+          ],
+          p: {
+            id: "sub-title"
+          },
+          t: "h2"
+        },
+        "\n",
+        {
+          c: ["Content"],
+          t: "p"
+        },
+        "\n",
+        {
+          c: [
+            {
+              c: [
+                {
+                  p: {
+                    className: "icon icon-link"
+                  },
+                  t: "span"
+                }
+              ],
+              p: {
+                "aria-hidden": true,
+                href: "#another-level-2"
+              },
+              t: "a"
+            },
+            "Another Level 2"
+          ],
+          p: {
+            id: "another-level-2"
+          },
+          t: "h2"
+        },
+        "\n",
+        {
+          c: [
+            {
+              c: [
+                {
+                  p: {
+                    className: "icon icon-link"
+                  },
+                  t: "span"
+                }
+              ],
+              p: {
+                "aria-hidden": true,
+                href: "#a-level-3"
+              },
+              t: "a"
+            },
+            "A level 3"
+          ],
+          p: {
+            id: "a-level-3"
+          },
+          t: "h3"
+        }
+      ],
+      t: "div"
+    })
+  ).toMatchSnapshot();
+});
diff --git a/packages/helpers-transform/src/extractMetaFromBodyNode.js b/packages/helpers-transform/src/extractMetaFromBodyNode.js
new file mode 100644
index 000000000..49417e2c5
--- /dev/null
+++ b/packages/helpers-transform/src/extractMetaFromBodyNode.js
@@ -0,0 +1,43 @@
+// @flow
+
+type Node =
+  | string
+  | {|
+      t?: string,
+      p?: Object,
+      c?: Node | $ReadOnlyArray<Node>
+    |};
+
+const renderText = (node?: Node) => {
+  if (!node) return "";
+  if (typeof node === "string") return node;
+  return Array.isArray(node.c)
+    ? node.c.map((child: Node) => renderText(child)).join("")
+    : renderText(node.c);
+};
+
+const getHeaders = (node?: Node) => {
+  if (!node) return [];
+  if (typeof node.t === "string") {
+    const tag = node.t;
+    const level = parseInt(tag[1], 10);
+    if (tag[0] === "h" && !isNaN(level)) {
+      return [[level, renderText(node)]];
+    }
+  }
+  return (Array.isArray(node.c)
+    ? // $FlowFixMe stfu
+      node.c.reduce((acc, child: Node) => acc.concat(getHeaders(child)), [])
+    : // $FlowFixMe stfu
+      getHeaders(node.c)
+  ).filter(h => h);
+};
+
+export default (node: Node) => {
+  const headers = getHeaders(node);
+  const firstH1 = headers.find(h => h[0] === 1);
+  return {
+    ...(firstH1 ? { title: firstH1[1] } : {}),
+    ...(headers.length > 0 ? { headers } : {})
+  };
+};