Files
outline/shared/editor/lib/markdown/serializer.ts
2022-02-05 10:15:40 -08:00

454 lines
14 KiB
TypeScript

/* eslint-disable @typescript-eslint/ban-ts-comment */
// @ts-nocheck
// https://raw.githubusercontent.com/ProseMirror/prosemirror-markdown/master/src/to_markdown.js
// forked for table support
// ::- A specification for serializing a ProseMirror document as
// Markdown/CommonMark text.
export class MarkdownSerializer {
// :: (Object<(state: MarkdownSerializerState, node: Node, parent: Node, index: number)>, Object)
// Construct a serializer with the given configuration. The `nodes`
// object should map node names in a given schema to function that
// take a serializer state and such a node, and serialize the node.
//
// The `marks` object should hold objects with `open` and `close`
// properties, which hold the strings that should appear before and
// after a piece of text marked that way, either directly or as a
// function that takes a serializer state and a mark, and returns a
// string. `open` and `close` can also be functions, which will be
// called as
//
// (state: MarkdownSerializerState, mark: Mark,
// parent: Fragment, index: number) → string
//
// Where `parent` and `index` allow you to inspect the mark's
// context to see which nodes it applies to.
//
// Mark information objects can also have a `mixable` property
// which, when `true`, indicates that the order in which the mark's
// opening and closing syntax appears relative to other mixable
// marks can be varied. (For example, you can say `**a *b***` and
// `*a **b***`, but not `` `a *b*` ``.)
//
// To disable character escaping in a mark, you can give it an
// `escape` property of `false`. Such a mark has to have the highest
// precedence (must always be the innermost mark).
//
// The `expelEnclosingWhitespace` mark property causes the
// serializer to move enclosing whitespace from inside the marks to
// outside the marks. This is necessary for emphasis marks as
// CommonMark does not permit enclosing whitespace inside emphasis
// marks, see: http://spec.commonmark.org/0.26/#example-330
constructor(nodes, marks) {
// :: Object<(MarkdownSerializerState, Node)> The node serializer
// functions for this serializer.
this.nodes = nodes;
// :: Object The mark serializer info.
this.marks = marks;
}
// :: (Node, ?Object) → string
// Serialize the content of the given node to
// [CommonMark](http://commonmark.org/).
serialize(content, options?: { tightLists?: boolean }) {
const state = new MarkdownSerializerState(this.nodes, this.marks, options);
state.renderContent(content);
return state.out;
}
}
// ::- This is an object used to track state and expose
// methods related to markdown serialization. Instances are passed to
// node and mark serialization methods (see `toMarkdown`).
export class MarkdownSerializerState {
inTable = false;
inTightList = false;
closed = false;
delim = "";
constructor(nodes, marks, options) {
this.nodes = nodes;
this.marks = marks;
this.delim = this.out = "";
this.closed = false;
this.inTightList = false;
this.inTable = false;
// :: Object
// The options passed to the serializer.
// tightLists:: ?bool
// Whether to render lists in a tight style. This can be overridden
// on a node level by specifying a tight attribute on the node.
// Defaults to false.
this.options = options || {};
if (typeof this.options.tightLists === "undefined") {
this.options.tightLists = true;
}
}
flushClose(size) {
if (this.closed) {
if (!this.atBlank()) {
this.out += "\n";
}
if (size === null || size === undefined) {
size = 2;
}
if (size > 1) {
let delimMin = this.delim;
const trim = /\s+$/.exec(delimMin);
if (trim) {
delimMin = delimMin.slice(0, delimMin.length - trim[0].length);
}
for (let i = 1; i < size; i++) {
this.out += delimMin + "\n";
}
}
this.closed = false;
}
}
// :: (string, ?string, Node, ())
// Render a block, prefixing each line with `delim`, and the first
// line in `firstDelim`. `node` should be the node that is closed at
// the end of the block, and `f` is a function that renders the
// content of the block.
wrapBlock(delim, firstDelim, node, f) {
const old = this.delim;
this.write(firstDelim || delim);
this.delim += delim;
f();
this.delim = old;
this.closeBlock(node);
}
atBlank() {
return /(^|\n)$/.test(this.out);
}
// :: ()
// Ensure the current content ends with a newline.
ensureNewLine() {
if (!this.atBlank()) {
this.out += "\n";
}
}
// :: (?string)
// Prepare the state for writing output (closing closed paragraphs,
// adding delimiters, and so on), and then optionally add content
// (unescaped) to the output.
write(content) {
this.flushClose();
if (this.delim && this.atBlank()) {
this.out += this.delim;
}
if (content) {
this.out += content;
}
}
// :: (Node)
// Close the block for the given node.
closeBlock(node) {
this.closed = node;
}
// :: (string, ?bool)
// Add the given text to the document. When escape is not `false`,
// it will be escaped.
text(text, escape) {
const lines = text.split("\n");
for (let i = 0; i < lines.length; i++) {
const startOfLine = this.atBlank() || this.closed;
this.write();
this.out += escape !== false ? this.esc(lines[i], startOfLine) : lines[i];
if (i !== lines.length - 1) {
this.out += "\n";
}
}
}
// :: (Node)
// Render the given node as a block.
render(node, parent, index) {
if (typeof parent === "number") {
throw new Error("!");
}
this.nodes[node.type.name](this, node, parent, index);
}
// :: (Node)
// Render the contents of `parent` as block nodes.
renderContent(parent) {
parent.forEach((node, _, i) => this.render(node, parent, i));
}
// :: (Node)
// Render the contents of `parent` as inline content.
renderInline(parent) {
const active = [];
let trailing = "";
const progress = (node, _, index) => {
let marks = node ? node.marks : [];
// Remove marks from `hard_break` that are the last node inside
// that mark to prevent parser edge cases with new lines just
// before closing marks.
// (FIXME it'd be nice if we had a schema-agnostic way to
// identify nodes that serialize as hard breaks)
if (node && node.type.name === "hard_break") {
marks = marks.filter((m) => {
if (index + 1 === parent.childCount) {
return false;
}
const next = parent.child(index + 1);
return (
m.isInSet(next.marks) && (!next.isText || /\S/.test(next.text))
);
});
}
let leading = trailing;
trailing = "";
// If whitespace has to be expelled from the node, adjust
// leading and trailing accordingly.
if (
node &&
node.isText &&
marks.some((mark) => {
const info = this.marks[mark.type.name]();
return info && info.expelEnclosingWhitespace;
})
) {
// eslint-disable-next-line @typescript-eslint/no-unused-vars, no-unused-vars
const [_, lead, inner, trail] = /^(\s*)(.*?)(\s*)$/m.exec(node.text);
leading += lead;
trailing = trail;
if (lead || trail) {
node = inner ? node.withText(inner) : null;
if (!node) {
marks = active;
}
}
}
const inner = marks.length && marks[marks.length - 1],
noEsc = inner && this.marks[inner.type.name]().escape === false;
const len = marks.length - (noEsc ? 1 : 0);
// Try to reorder 'mixable' marks, such as em and strong, which
// in Markdown may be opened and closed in different order, so
// that order of the marks for the token matches the order in
// active.
outer: for (let i = 0; i < len; i++) {
const mark = marks[i];
if (!this.marks[mark.type.name]().mixable) {
break;
}
for (let j = 0; j < active.length; j++) {
const other = active[j];
if (!this.marks[other.type.name]().mixable) {
break;
}
if (mark.eq(other)) {
if (i > j) {
marks = marks
.slice(0, j)
.concat(mark)
.concat(marks.slice(j, i))
.concat(marks.slice(i + 1, len));
} else if (j > i) {
marks = marks
.slice(0, i)
.concat(marks.slice(i + 1, j))
.concat(mark)
.concat(marks.slice(j, len));
}
continue outer;
}
}
}
// Find the prefix of the mark set that didn't change
let keep = 0;
while (
keep < Math.min(active.length, len) &&
marks[keep].eq(active[keep])
) {
++keep;
}
// Close the marks that need to be closed
while (keep < active.length) {
this.text(this.markString(active.pop(), false, parent, index), false);
}
// Output any previously expelled trailing whitespace outside the marks
if (leading) {
this.text(leading);
}
// Open the marks that need to be opened
if (node) {
while (active.length < len) {
const add = marks[active.length];
active.push(add);
this.text(this.markString(add, true, parent, index), false);
}
// Render the node. Special case code marks, since their content
// may not be escaped.
if (noEsc && node.isText) {
this.text(
this.markString(inner, true, parent, index) +
node.text +
this.markString(inner, false, parent, index + 1),
false
);
} else {
this.render(node, parent, index);
}
}
};
parent.forEach(progress);
progress(null, null, parent.childCount);
}
// :: (Node, string, (number) → string)
// Render a node's content as a list. `delim` should be the extra
// indentation added to all lines except the first in an item,
// `firstDelim` is a function going from an item index to a
// delimiter for the first line of the item.
renderList(node, delim, firstDelim) {
if (this.closed && this.closed.type === node.type) {
this.flushClose(3);
} else if (this.inTightList) {
this.flushClose(1);
}
const isTight =
typeof node.attrs.tight !== "undefined"
? node.attrs.tight
: this.options.tightLists;
const prevTight = this.inTightList;
const prevList = this.inList;
this.inList = true;
this.inTightList = isTight;
node.forEach((child, _, i) => {
if (i && isTight) {
this.flushClose(1);
}
this.wrapBlock(delim, firstDelim(i), node, () =>
this.render(child, node, i)
);
});
this.inList = prevList;
this.inTightList = prevTight;
}
renderTable(node) {
this.flushClose(1);
let headerBuffer = "";
const prevTable = this.inTable;
this.inTable = true;
// ensure there is an empty newline above all tables
this.out += "\n";
// rows
node.forEach((row, _, i) => {
// cols
row.forEach((cell, _, j) => {
this.out += j === 0 ? "| " : " | ";
cell.forEach((para) => {
// just padding the output so that empty cells take up the same space
// as headings.
// TODO: Ideally we'd calc the longest cell length and use that
// to pad all the others.
if (para.textContent === "" && para.content.size === 0) {
this.out += " ";
} else {
this.closed = false;
this.render(para, row, j);
}
});
if (i === 0) {
if (cell.attrs.alignment === "center") {
headerBuffer += "|:---:";
} else if (cell.attrs.alignment === "left") {
headerBuffer += "|:---";
} else if (cell.attrs.alignment === "right") {
headerBuffer += "|---:";
} else {
headerBuffer += "|----";
}
}
});
this.out += " |\n";
if (headerBuffer) {
this.out += `${headerBuffer}|\n`;
headerBuffer = undefined;
}
});
this.inTable = prevTable;
}
// :: (string, ?bool) → string
// Escape the given string so that it can safely appear in Markdown
// content. If `startOfLine` is true, also escape characters that
// has special meaning only at the start of the line.
esc(str = "", startOfLine) {
str = str.replace(/[`*\\~[\]]/g, "\\$&");
if (startOfLine) {
str = str.replace(/^[:#\-*+]/, "\\$&").replace(/^(\d+)\./, "$1\\.");
}
if (this.inTable) {
str = str.replace(/\|/gi, "\\$&");
}
return str;
}
quote(str) {
const wrap =
str.indexOf('"') === -1 ? '""' : str.indexOf("'") === -1 ? "''" : "()";
return wrap[0] + str + wrap[1];
}
// :: (string, number) → string
// Repeat the given string `n` times.
repeat(str, n) {
let out = "";
for (let i = 0; i < n; i++) {
out += str;
}
return out;
}
// : (Mark, bool, string?) → string
// Get the markdown string for a given opening or closing mark.
markString(mark, open, parent, index) {
const info = this.marks[mark.type.name]();
const value = open ? info.open : info.close;
return typeof value === "string" ? value : value(this, mark, parent, index);
}
// :: (string) → { leading: ?string, trailing: ?string }
// Get leading and trailing whitespace from a string. Values of
// leading or trailing property of the return object will be undefined
// if there is no match.
getEnclosingWhitespace(text) {
return {
leading: (text.match(/^(\s+)/) || [])[0],
trailing: (text.match(/(\s+)$/) || [])[0],
};
}
}