feat(changelog): add support for changelog blocks

package.json

@@ -34,6 +34,7 @@
     "chalk": "4.1.2",
     "get-root-node-polyfill": "1.0.0",
     "github-slugger": "1.4.0",
+    "js-yaml": "^4.1.0",
     "lodash": "4.17.21",
     "markdown-it": "13.0.1",
     "markdown-it-attrs": "4.1.4",
@@ -56,6 +57,7 @@
     "@types/github-slugger": "1.3.0",
     "@types/highlight.js": "10.1.0",
     "@types/jest": "28.1.7",
+    "@types/js-yaml": "^4.0.5",
     "@types/lodash": "4.14.183",
     "@types/markdown-it": "12.2.3",
     "@types/markdown-it-attrs": "4.1.0",

src/transform/plugins/changelog/collect.ts

@@ -0,0 +1,60 @@
+import {bold} from 'chalk';
+import {ChangelogItem} from './types';
+import initMarkdownit from '../../md';
+import changelogPlugin from './index';
+import imsize from '../imsize';
+import {MarkdownItPluginOpts} from '../typings';
+
+const BLOCK_START = '{% changelog %}';
+const BLOCK_END = '{% endchangelog %}\n';
+
+function parseChangelogs(str: string, path?: string) {
+    const {parse, compile, env} = initMarkdownit({
+        plugins: [changelogPlugin, imsize],
+        extractChangelogs: true,
+        path,
+    });
+
+    compile(parse(str));
+
+    return env.changelogs || [];
+}
+
+type Options = Pick<MarkdownItPluginOpts, 'path' | 'log'> & {
+    changelogs?: ChangelogItem[];
+    extractChangelogs?: boolean;
+};
+
+const collect = (input: string, {path: filepath, log, changelogs, extractChangelogs}: Options) => {
+    let result = input;
+    let lastPos = 0;
+    const rawChanges = [];
+
+    // eslint-disable-next-line no-constant-condition
+    while (true) {
+        const pos = result.indexOf(BLOCK_START, lastPos);
+        lastPos = pos;
+        if (pos === -1) {
+            break;
+        }
+        const endPos = result.indexOf(BLOCK_END, pos + BLOCK_START.length);
+        if (endPos === -1) {
+            log.error(`Changelog block must be closed${filepath ? ` in ${bold(filepath)}` : ''}`);
+            break;
+        }
+
+        const change = result.slice(pos, endPos + BLOCK_END.length);
+
+        rawChanges.push(change);
+
+        result = result.slice(0, pos) + result.slice(endPos + BLOCK_END.length);
+    }
+
+    if (rawChanges.length && changelogs && extractChangelogs) {
+        changelogs.push(...parseChangelogs(rawChanges.join('\n\n'), filepath));
+    }
+
+    return result;
+};
+
+export = collect;

src/transform/plugins/changelog/index.ts

@@ -0,0 +1,165 @@
+import {MarkdownItPluginCb} from '../typings';
+import Core from 'markdown-it/lib/parser_core';
+import Token from 'markdown-it/lib/token';
+import {bold} from 'chalk';
+import yaml from 'js-yaml';
+import StateCore from 'markdown-it/lib/rules_core/state_core';
+
+interface Metadata {
+    date: string;
+}
+
+interface Options {
+    extractChangelogs?: boolean;
+}
+
+const CHANGELOG_OPEN_RE = /^\{% changelog %}/;
+const CHANGELOG_CLOSE_RE = /^\{% endchangelog %}/;
+
+function isOpenToken(tokens: Token[], i: number) {
+    return (
+        tokens[i].type === 'paragraph_open' &&
+        tokens[i + 1].type === 'inline' &&
+        tokens[i + 2].type === 'paragraph_close' &&
+        CHANGELOG_OPEN_RE.test(tokens[i + 1].content)
+    );
+}
+
+function isCloseToken(tokens: Token[], i: number) {
+    return (
+        tokens[i]?.type === 'paragraph_open' &&
+        tokens[i + 1].type === 'inline' &&
+        tokens[i + 2].type === 'paragraph_close' &&
+        CHANGELOG_CLOSE_RE.test(tokens[i + 1].content)
+    );
+}
+
+function isTitle(tokens: Token[], i = 0) {
+    return (
+        tokens[i].type === 'heading_open' &&
+        tokens[i + 1].type === 'inline' &&
+        tokens[i + 2].type === 'heading_close'
+    );
+}
+
+function isImageParagraph(tokens: Token[], i = 0) {
+    return (
+        tokens[i].type === 'paragraph_open' &&
+        tokens[i + 1].type === 'inline' &&
+        tokens[i + 2].type === 'paragraph_close' &&
+        tokens[i + 1].children?.some((t) => t.type === 'image')
+    );
+}
+
+function parseBody(tokens: Token[], state: StateCore) {
+    const {md, env} = state;
+
+    const metadataToken = tokens.shift();
+    if (metadataToken?.type !== 'fence') {
+        throw new Error('Metadata tag not found');
+    }
+    const rawMetadata = yaml.load(metadataToken.content) as Metadata;
+    const metadata = {
+        ...rawMetadata,
+        date: new Date(rawMetadata.date).toISOString(),
+    };
+
+    if (!isTitle(tokens)) {
+        throw new Error('Title tag not found');
+    }
+    const title = tokens.splice(0, 3)[1].content;
+
+    let image;
+    if (isImageParagraph(tokens)) {
+        const paragraphTokens = tokens.splice(0, 3);
+        const imageToken = paragraphTokens[1]?.children?.find((token) => token.type === 'image');
+        if (imageToken) {
+            const width = Number(imageToken.attrGet('width'));
+            const height = Number(imageToken.attrGet('height'));
+            let ratio;
+            if (Number.isFinite(width) && Number.isFinite(height)) {
+                ratio = height / width;
+            }
+            let alt = imageToken.attrGet('title') || '';
+            if (!alt && imageToken.children) {
+                alt = md.renderer.renderInlineAsText(imageToken.children, md.options, env);
+            }
+            image = {
+                src: imageToken.attrGet('src'),
+                alt,
+                ratio,
+            };
+        }
+    }
+
+    const description = md.renderer.render(tokens, md.options, env);
+
+    return {
+        ...metadata,
+        title,
+        image,
+        description,
+    };
+}
+
+const changelog: MarkdownItPluginCb<Options> = function (md, {extractChangelogs, log, path}) {
+    const plugin: Core.RuleCore = (state) => {
+        const {tokens, env} = state;
+
+        for (let i = 0, len = tokens.length; i < len; i++) {
+            const isOpen = isOpenToken(tokens, i);
+            if (!isOpen) continue;
+
+            const openAt = i;
+            let isCloseFound = false;
+            while (i < len) {
+                i++;
+                if (isCloseToken(tokens, i)) {
+                    isCloseFound = true;
+                    break;
+                }
+            }
+
+            if (!isCloseFound) {
+                log.error(`Changelog close tag in not found: ${bold(path)}`);
+                break;
+            }
+
+            const closeAt = i + 2;
+
+            if (env && extractChangelogs) {
+                const content = tokens.slice(openAt, closeAt + 1);
+
+                // cut open
+                content.splice(0, 3);
+                // cut close
+                content.splice(-3);
+
+                try {
+                    const change = parseBody(content, state);
+
+                    if (!env.changelogs) {
+                        env.changelogs = [];
+                    }
+
+                    env.changelogs.push(change);
+                } catch (err) {
+                    log.error(`Changelog error: ${(err as Error).message} in ${bold(path)}`);
+                    continue;
+                }
+            }
+
+            tokens.splice(openAt, closeAt + 1 - openAt);
+            len = tokens.length;
+            i = openAt - 1;
+        }
+    };
+
+    try {
+        md.core.ruler.before('curly_attributes', 'changelog', plugin);
+    } catch (e) {
+        md.core.ruler.push('changelog', plugin);
+    }
+};
+
+export = changelog;

src/transform/plugins/changelog/types.ts

@@ -0,0 +1,11 @@
+export interface ChangelogItem {
+    title: string;
+    image: {
+        src: string;
+        alt: string;
+        ratio?: string;
+    };
+    description: string;
+    date: string;
+    [x: string]: unknown;
+}