(chore) Docs: add tag to produce only a diagram, not code example

packages/mermaid/src/docs.mts

@@ -48,14 +48,26 @@ const MERMAID_MAJOR_VERSION = (
 ).split('.')[0];
 const CDN_URL = 'https://cdn.jsdelivr.net/npm'; // 'https://unpkg.com';
 
+const MERMAID_KEYWORD = 'mermaid';
+const MERMAID_CODE_ONLY_KEYWORD = 'mermaid-example';
+
+// These keywords will produce both a mermaid diagram and a code block with the diagram source
+const MERMAID_EXAMPLE_KEYWORDS = [MERMAID_KEYWORD, 'mmd', MERMAID_CODE_ONLY_KEYWORD]; // 'mmd' is an old keyword that used to be used
+
+// This keyword will only produce a mermaid diagram
+const MERMAID_DIAGRAM_ONLY = 'mermaid-nocode';
+
+// These will be transformed into block quotes
+const BLOCK_QUOTE_KEYWORDS = ['note', 'tip', 'warning', 'danger'];
+
+// options for running the main command
 const verifyOnly: boolean = process.argv.includes('--verify');
 const git: boolean = process.argv.includes('--git');
 const watch: boolean = process.argv.includes('--watch');
 const vitepress: boolean = process.argv.includes('--vitepress');
 const noHeader: boolean = process.argv.includes('--noHeader') || vitepress;
 
-// These paths are from the root of the mono-repo, not from the
-// mermaid sub-directory
+// These paths are from the root of the mono-repo, not from the mermaid subdirectory
 const SOURCE_DOCS_DIR = 'src/docs';
 const FINAL_DOCS_DIR = vitepress ? 'src/vitepress' : '../../docs';
 
@@ -153,7 +165,11 @@ const blockIcons: Record<string, string> = {
 
 const capitalize = (word: string) => word[0].toUpperCase() + word.slice(1);
 
-const transformToBlockQuote = (content: string, type: string, customTitle?: string | null) => {
+export const transformToBlockQuote = (
+  content: string,
+  type: string,
+  customTitle?: string | null
+) => {
   if (vitepress) {
     const vitepressType = type === 'note' ? 'info' : type;
     return `::: ${vitepressType} ${customTitle || ''}\n${content}\n:::`;
@@ -180,41 +196,67 @@ const transformIncludeStatements = (file: string, text: string): string => {
     }
   });
 };
+
 /**
- * Transform a markdown file and write the transformed file to the directory for published
- * documentation
+ * Transform code blocks in a Markdown file.
+ * Use remark.parse() to turn the given content (a String) into an AST.
+ * For any AST node that is a code block: transform it as needed:
+ * - blocks marked as MERMAID_DIAGRAM_ONLY will be set to a 'mermaid' code block so it will be rendered as (only) a diagram
+ * - blocks marked as MERMAID_EXAMPLE_KEYWORDS will be copied and the original node will be a code only block and the copy with be rendered as the diagram
+ * - blocks marked as BLOCK_QUOTE_KEYWORDS will be transformed into block quotes
  *
- * 1. Add a `mermaid-example` block before every `mermaid` or `mmd` block On the docsify site (one
- *    place where the documentation is published), this will show the code used for the mermaid
- *    diagram
- * 2. Add the text that says the file is automatically generated
- * 3. Use prettier to format the file Verify that the file has been changed and write out the changes
+ * Convert the AST back to a string and return it.
  *
- * @param file {string} name of the file that will be verified
+ * @param content - the contents of a Markdown file
+ * @returns the contents with transformed code blocks
  */
-const transformMarkdown = (file: string) => {
-  const doc = injectPlaceholders(transformIncludeStatements(file, readSyncedUTF8file(file)));
-  const ast: Root = remark.parse(doc);
-  const out = flatmap(ast, (c: Code) => {
-    if (c.type !== 'code' || !c.lang) {
-      return [c];
+export const transformBlocks = (content: string): string => {
+  const ast: Root = remark.parse(content);
+  const astWithTransformedBlocks = flatmap(ast, (node: Code) => {
+    if (node.type !== 'code' || !node.lang) {
+      return [node]; // no transformation if this is not a code block
     }
 
-    // Convert mermaid code blocks to mermaid-example blocks
-    if (['mermaid', 'mmd', 'mermaid-example'].includes(c.lang)) {
-      c.lang = 'mermaid-example';
-      return [c, Object.assign({}, c, { lang: 'mermaid' })];
+    if (node.lang === MERMAID_DIAGRAM_ONLY) {
+      // Set the lang to 'mermaid' so it will be rendered as a diagram.
+      node.lang = MERMAID_KEYWORD;
+      return [node];
+    } else if (MERMAID_EXAMPLE_KEYWORDS.includes(node.lang)) {
+      // Return 2 nodes:
+      //   1. the original node with the language now set to 'mermaid-example' (will be rendered as code), and
+      //   2. a copy of the original node with the language set to 'mermaid' (will be rendered as a diagram)
+      node.lang = MERMAID_CODE_ONLY_KEYWORD;
+      return [node, Object.assign({}, node, { lang: MERMAID_KEYWORD })];
     }
 
-    // Transform codeblocks into block quotes.
-    if (['note', 'tip', 'warning', 'danger'].includes(c.lang)) {
-      return [remark.parse(transformToBlockQuote(c.value, c.lang, c.meta))];
+    // Transform these blocks into block quotes.
+    if (BLOCK_QUOTE_KEYWORDS.includes(node.lang)) {
+      return [remark.parse(transformToBlockQuote(node.value, node.lang, node.meta))];
     }
 
-    return [c];
+    return [node]; // default is to do nothing to the node
   });
 
-  let transformed = remark.stringify(out);
+  return remark.stringify(astWithTransformedBlocks);
+};
+
+/**
+ * Transform a markdown file and write the transformed file to the directory for published
+ * documentation
+ *
+ * 1. include any included files (copy and insert the source)
+ * 2. Add a `mermaid-example` block before every `mermaid` or `mmd` block On the main documentation site (one
+ *    place where the documentation is published), this will show the code for the mermaid diagram
+ * 3. Transform blocks to block quotes as needed
+ * 4. Add the text that says the file is automatically generated
+ * 5. Use prettier to format the file.
+ * 6. Verify that the file has been changed and write out the changes
+ *
+ * @param file {string} name of the file that will be verified
+ */
+const transformMarkdown = (file: string) => {
+  const doc = injectPlaceholders(transformIncludeStatements(file, readSyncedUTF8file(file)));
+  let transformed = transformBlocks(doc);
   if (!noHeader) {
     // Add the header to the start of the file
     transformed = `${generateHeader(file)}\n${transformed}`;

packages/mermaid/src/docs.spec.ts

@@ -0,0 +1,115 @@
+import { transformBlocks, transformToBlockQuote } from './docs.mjs';
+
+import { remark } from 'remark'; // import it this way so we can mock it
+vi.mock('remark');
+
+afterEach(() => {
+  vi.restoreAllMocks();
+});
+
+describe('docs.mts', () => {
+  describe('transformBlocks', () => {
+    it('uses remark.parse to create the AST for the file ', () => {
+      const remarkParseSpy = vi
+        .spyOn(remark, 'parse')
+        .mockReturnValue({ type: 'root', children: [] });
+      const contents = 'Markdown file contents';
+      transformBlocks(contents);
+      expect(remarkParseSpy).toHaveBeenCalledWith(contents);
+    });
+    describe('checks each AST node', () => {
+      it('does no transformation if there are no code blocks', async () => {
+        const contents = 'Markdown file contents\n';
+        const result = transformBlocks(contents);
+        expect(result).toEqual(contents);
+      });
+
+      describe('is a code block', () => {
+        const beforeCodeLine = 'test\n';
+        const diagram_text = 'graph\n A --> B\n';
+
+        describe('language = "mermaid-nocode"', () => {
+          const lang_keyword = 'mermaid-nocode';
+          const contents = beforeCodeLine + '```' + lang_keyword + '\n' + diagram_text + '\n```\n';
+
+          it('changes the language to "mermaid"', () => {
+            const result = transformBlocks(contents);
+            expect(result).toEqual(
+              beforeCodeLine + '\n' + '```' + 'mermaid' + '\n' + diagram_text + '\n```\n'
+            );
+          });
+        });
+
+        describe('language = "mermaid" | "mmd" | "mermaid-example"', () => {
+          const mermaid_keywords = ['mermaid', 'mmd', 'mermaid-example'];
+
+          mermaid_keywords.forEach((lang_keyword) => {
+            const contents =
+              beforeCodeLine + '```' + lang_keyword + '\n' + diagram_text + '\n```\n';
+
+            it('changes the language to "mermaid-example" and adds a copy of the code block with language = "mermaid"', () => {
+              const result = transformBlocks(contents);
+              expect(result).toEqual(
+                beforeCodeLine +
+                  '\n' +
+                  '```mermaid-example\n' +
+                  diagram_text +
+                  '\n```\n' +
+                  '\n```mermaid\n' +
+                  diagram_text +
+                  '\n```\n'
+              );
+            });
+          });
+        });
+
+        it('calls transformToBlockQuote with the node information', () => {
+          const lang_keyword = 'note';
+          const contents =
+            beforeCodeLine + '```' + lang_keyword + '\n' + 'This is the text\n' + '```\n';
+
+          const result = transformBlocks(contents);
+          expect(result).toEqual(beforeCodeLine + '\n> **Note**\n' + '> This is the text\n');
+        });
+      });
+    });
+  });
+
+  describe('transformToBlockQuote', () => {
+    // TODO Is there a way to test this with --vitepress given as a process argument?
+
+    describe('vitepress is not given as an argument', () => {
+      it('everything starts with "> " (= block quote)', () => {
+        const result = transformToBlockQuote('first line\n\n\nfourth line', 'blorfType');
+        expect(result).toMatch(/> (.)*\n> first line(?:\n> ){3}fourth line/);
+      });
+
+      it('includes an icon if there is one for the type', () => {
+        const result = transformToBlockQuote(
+          'first line\n\n\nfourth line',
+          'danger',
+          'Custom Title'
+        );
+        expect(result).toMatch(/> \*\*‼️ Custom Title\*\* /);
+      });
+
+      describe('a custom title is given', () => {
+        it('custom title is surrounded in spaces, in bold', () => {
+          const result = transformToBlockQuote(
+            'first line\n\n\nfourth line',
+            'blorfType',
+            'Custom Title'
+          );
+          expect(result).toMatch(/> \*\*Custom Title\*\* /);
+        });
+      });
+
+      describe.skip('no custom title is given', () => {
+        it('title is the icon and the capitalized type, in bold', () => {
+          const result = transformToBlockQuote('first line\n\n\nfourth line', 'blorf type');
+          expect(result).toMatch(/> \*\*Blorf Type\*\* /);
+        });
+      });
+    });
+  });
+});