From b4d1053bb42acde9218f0f47a1dca5690b01fc5d Mon Sep 17 00:00:00 2001
From: Sosuke Suzuki <aosukeke@gmail.com>
Date: Fri, 5 Jun 2020 18:47:24 +0900
Subject: [PATCH] Refactor: Use `normalizeParts` from `document/utils` in
 `printer-markdown` (#8496)

* Use normalizeParts from utils in printer-markdown

* Remove flatting for concat from normalizeDoc

* Fix undef parts

* Move normalizeDoc to doc-utils

* Add test for normalizeDoc

* Modify tests to avoid specllcheck errors
---
 src/document/doc-utils.js                    | 13 ++++++
 src/language-markdown/printer-markdown.js    | 42 +-------------------
 tests_integration/__tests__/normalize-doc.js | 42 ++++++++++++++++++++
 3 files changed, 56 insertions(+), 41 deletions(-)
 create mode 100644 tests_integration/__tests__/normalize-doc.js

diff --git a/src/document/doc-utils.js b/src/document/doc-utils.js
index bf939b416..dfece63b6 100644
--- a/src/document/doc-utils.js
+++ b/src/document/doc-utils.js
@@ -250,6 +250,18 @@ function normalizeParts(parts) {
   return newParts;
 }
 
+function normalizeDoc(doc) {
+  return mapDoc(doc, (currentDoc) => {
+    if (!currentDoc.parts) {
+      return currentDoc;
+    }
+    return {
+      ...currentDoc,
+      parts: normalizeParts(currentDoc.parts),
+    };
+  });
+}
+
 module.exports = {
   isEmpty,
   willBreak,
@@ -261,4 +273,5 @@ module.exports = {
   removeLines,
   stripTrailingHardline,
   normalizeParts,
+  normalizeDoc,
 };
diff --git a/src/language-markdown/printer-markdown.js b/src/language-markdown/printer-markdown.js
index 7a3b07b9d..9cc69d2ac 100644
--- a/src/language-markdown/printer-markdown.js
+++ b/src/language-markdown/printer-markdown.js
@@ -20,7 +20,7 @@ const {
     indent,
     group,
   },
-  utils: { mapDoc },
+  utils: { normalizeDoc },
   printer: { printDocToString },
 } = require("../document");
 const {
@@ -851,32 +851,6 @@ function shouldRemainTheSameContent(path) {
   );
 }
 
-function normalizeDoc(doc) {
-  return mapDoc(doc, (currentDoc) => {
-    if (!currentDoc.parts) {
-      return currentDoc;
-    }
-
-    if (currentDoc.type === "concat" && currentDoc.parts.length === 1) {
-      return currentDoc.parts[0];
-    }
-
-    const parts = currentDoc.parts.reduce((parts, part) => {
-      if (part.type === "concat") {
-        parts.push(...part.parts);
-      } else if (part !== "") {
-        parts.push(part);
-      }
-      return parts;
-    }, []);
-
-    return {
-      ...currentDoc,
-      parts: normalizeParts(parts),
-    };
-  });
-}
-
 function printUrl(url, dangerousCharOrChars) {
   const dangerousChars = [" "].concat(dangerousCharOrChars || []);
   return new RegExp(dangerousChars.map((x) => `\\${x}`).join("|")).test(url)
@@ -913,20 +887,6 @@ function printTitle(title, options, printSpace) {
   return `${quote}${title}${quote}`;
 }
 
-function normalizeParts(parts) {
-  return parts.reduce((current, part) => {
-    const lastPart = privateUtil.getLast(current);
-
-    if (typeof lastPart === "string" && typeof part === "string") {
-      current.splice(-1, 1, lastPart + part);
-    } else {
-      current.push(part);
-    }
-
-    return current;
-  }, []);
-}
-
 function clamp(value, min, max) {
   return value < min ? min : value > max ? max : value;
 }
diff --git a/tests_integration/__tests__/normalize-doc.js b/tests_integration/__tests__/normalize-doc.js
new file mode 100644
index 000000000..e4b362733
--- /dev/null
+++ b/tests_integration/__tests__/normalize-doc.js
@@ -0,0 +1,42 @@
+"use strict";
+
+const prettier = require("prettier/local");
+const docBuilders = prettier.doc.builders;
+const docUtils = prettier.doc.utils;
+
+const { normalizeDoc } = docUtils;
+const { group, concat, fill } = docBuilders;
+
+describe("normalizeDoc", () => {
+  test.each([
+    [
+      "removes empty strings",
+      concat(["", "foo", fill(["", "bar", ""]), ""]),
+      concat(["foo", fill(["bar"])]),
+    ],
+    [
+      "flattens nested concat",
+      concat(["foo ", "", concat(["bar ", "", concat(["baz", ""])])]),
+      concat(["foo bar baz"]),
+    ],
+    [
+      "flattens nested concat in other docs",
+      group(concat(["foo ", concat(["bar ", "", concat(["baz", ""])])])),
+      group(concat(["foo bar baz"])),
+    ],
+    [
+      "keeps groups",
+      concat([group("foo"), group("bar"), group("baz")]),
+      concat([group("foo"), group("bar"), group("baz")]),
+    ],
+    [
+      "keeps fills",
+      fill(["foo", fill(["bar", fill(["baz"])])]),
+      fill(["foo", fill(["bar", fill(["baz"])])]),
+    ],
+  ])("%s", (_, doc, expected) => {
+    const result = normalizeDoc(doc);
+
+    expect(result).toEqual(expected);
+  });
+});