Adding remove_obsidian_comments postprocessor to remove obsidian format comments

README.md

@@ -239,6 +239,30 @@ With these hooks in place, links to both notes as well as file attachments shoul
  > 
  > Note: If you're using a theme which comes with it's own render hooks, you might need to do a little extra work, or customize the snippets above, to avoid conflicts with the hooks from your theme.
 
+## Removing Obsidian comments
+
+To remove [Obsidian formatted comments](https://help.obsidian.md/Editing+and+formatting/Basic+formatting+syntax#Comments) you can set the `--remove-obsidian-comments` flag. This will remove inline as well as block comments but leave any comments found in codeblocks.
+
+````md
+This is not a comment.
+
+%% This is an inline comment %% This line could have more text.
+
+%%
+This would be a
+block comment and
+all of this would be removed
+%%
+````
+
+With the `--remove-obsidian-comments` flag. This file would output as
+
+````md
+This is not a comment
+
+This line could have more text.
+````
+
 
 # Library usage
 

docs/usage-advanced.md

@@ -118,3 +118,30 @@ With these hooks in place, links to both notes as well as file attachments shoul
 [hugo-relative-linking]: https://notes.nick.groenen.me/notes/relative-linking-in-hugo/
 [hugo]: https://gohugo.io
 [markdown render hooks]: https://gohugo.io/getting-started/configuration-markup#markdown-render-hooks
+
+## Removing Obsidian comments
+
+By default, comments are kept unchanged in the output.
+
+To remove [Obsidian formatted comments](https://help.obsidian.md/Editing+and+formatting/Basic+formatting+syntax#Comments) you can set the `--comments=remove` flag. This will remove inline as well as block comments but leave any comments found in codeblocks.
+
+```md
+This is not a comment.
+
+%% This is an inline comment %% This line could have more text.
+
+%%
+This would be a
+block comment and
+all of this would be removed
+%%
+```
+With the `--comments=remove` flag. This file would output as
+
+```md
+This is not a comment
+
+This line could have more text.
+```
+
+> Note: Comments within codeblocks are left untouched

src/main.rs

@@ -3,7 +3,12 @@ use std::path::PathBuf;
 
 use eyre::{eyre, Result};
 use gumdrop::Options;
-use obsidian_export::postprocessors::{filter_by_tags, softbreaks_to_hardbreaks};
+use obsidian_export::postprocessors::{
+    filter_by_tags,
+    remove_obsidian_comments,
+    softbreaks_to_hardbreaks,
+    CommentStrategy,
+};
 use obsidian_export::{ExportError, Exporter, FrontmatterStrategy, WalkOptions};
 
 const VERSION: &str = env!("CARGO_PKG_VERSION");
@@ -70,6 +75,15 @@ struct Opts {
         default = "false"
     )]
     hard_linebreaks: bool,
+
+    #[options(
+        no_short,
+        help = "Comment strategy (one of: keep-unchanged or remove)",
+        long = "comments",
+        parse(try_from_str = "comment_strategy_from_str"),
+        default = "keep-unchanged"
+    )]
+    comment_strategy: CommentStrategy,
 }
 
 fn frontmatter_strategy_from_str(input: &str) -> Result<FrontmatterStrategy> {
@@ -81,6 +95,14 @@ fn frontmatter_strategy_from_str(input: &str) -> Result<FrontmatterStrategy> {
     }
 }
 
+fn comment_strategy_from_str(input: &str) -> Result<CommentStrategy> {
+    match input {
+        "keep-unchanged" => Ok(CommentStrategy::KeepUnchanged),
+        "remove" => Ok(CommentStrategy::Remove),
+        _ => Err(eyre!("must be one of: keep-unchanged or remove")),
+    }
+}
+
 fn main() {
     // Due to the use of free arguments in Opts, we must bypass Gumdrop to determine whether the
     // version flag was specified. Without this, "missing required free argument" would get printed
@@ -111,6 +133,10 @@ fn main() {
         exporter.add_postprocessor(&softbreaks_to_hardbreaks);
     }
 
+    if matches!(args.comment_strategy, CommentStrategy::Remove) {
+        exporter.add_postprocessor(&remove_obsidian_comments);
+    }
+
     let tags_postprocessor = filter_by_tags(args.skip_tags, args.only_tags);
     exporter.add_postprocessor(&tags_postprocessor);
 

src/postprocessors.rs

@@ -1,6 +1,9 @@
 //! A collection of officially maintained [postprocessors][crate::Postprocessor].
 
-use pulldown_cmark::Event;
+use std::cell::LazyCell;
+
+use pulldown_cmark::{CowStr, Event, Tag};
+use regex::Regex;
 use serde_yaml::Value;
 
 use super::{Context, MarkdownEvents, PostprocessorResult};
@@ -52,6 +55,94 @@ fn filter_by_tags_(
     }
 }
 
+//Available strategies for what to do with comments
+#[derive(Debug)]
+#[non_exhaustive]
+pub enum CommentStrategy {
+    // Leave comments alone and export them as normal
+    KeepUnchanged,
+    // Remove any comments from the output
+    Remove,
+}
+
+#[allow(clippy::arithmetic_side_effects)]
+/// This postprocessor removes all Obsidian comments from a file excluding codeblocks. Enabling this
+/// prohibits comments from being exported but leaves them untouched in the original files
+pub fn remove_obsidian_comments(
+    _context: &mut Context,
+    events: &mut MarkdownEvents<'_>,
+) -> PostprocessorResult {
+    let mut output = Vec::with_capacity(events.len());
+    let mut inside_comment = false;
+    let mut inside_codeblock = false;
+    let re = LazyCell::new(|| Regex::new(r"%%.*?%%").unwrap());
+
+    for event in &mut *events {
+        output.push(event.to_owned());
+
+        match event {
+            Event::Text(ref text) => {
+                if !text.contains("%%") {
+                    if inside_comment {
+                        output.pop(); //Inside block comment so remove
+                    }
+                    continue;
+                }
+
+                if inside_codeblock {
+                    continue; //Skip anything inside codeblocks
+                }
+
+                output.pop();
+
+                if inside_comment {
+                    inside_comment = false;
+                    continue;
+                }
+
+                if !text.eq(&CowStr::from("%%")) {
+                    let result = re.replace_all(text, "").to_string();
+                    output.push(Event::Text(CowStr::from(result)));
+                    continue;
+                }
+
+                inside_comment = true;
+            }
+            Event::Start(Tag::CodeBlock(_)) => {
+                if inside_comment {
+                    output.pop();
+                } else {
+                    inside_codeblock = true;
+                }
+            }
+            Event::End(Tag::CodeBlock(_)) => {
+                if inside_comment {
+                    output.pop();
+                } else {
+                    inside_codeblock = false;
+                }
+            }
+            Event::End(Tag::Paragraph) => {
+                if output.len() >= 2
+                    && output.get(output.len() - 2) == Option::from(&Event::Start(Tag::Paragraph))
+                {
+                    // If the comment was the only item on the line remove the start and end
+                    // paragraph events to remove the \n in the output file.
+                    output.pop();
+                    output.pop();
+                }
+            }
+            _ => {
+                if inside_comment {
+                    output.pop();
+                }
+            }
+        }
+    }
+    *events = output;
+    PostprocessorResult::Continue
+}
+
 #[test]
 fn test_filter_tags() {
     let tags = vec![

tests/postprocessors_test.rs

@@ -3,7 +3,11 @@ use std::fs::{read_to_string, remove_file};
 use std::path::PathBuf;
 use std::sync::Mutex;
 
-use obsidian_export::postprocessors::{filter_by_tags, softbreaks_to_hardbreaks};
+use obsidian_export::postprocessors::{
+    filter_by_tags,
+    remove_obsidian_comments,
+    softbreaks_to_hardbreaks,
+};
 use obsidian_export::{Context, Exporter, MarkdownEvents, PostprocessorResult};
 use pretty_assertions::assert_eq;
 use pulldown_cmark::{CowStr, Event};
@@ -295,3 +299,20 @@ fn test_filter_by_tags() {
         );
     }
 }
+
+#[test]
+fn test_remove_obsidian_comments() {
+    let tmp_dir = TempDir::new().expect("failed to make tempdir");
+    let mut exporter = Exporter::new(
+        PathBuf::from("tests/testdata/input/remove-comments/"),
+        tmp_dir.path().to_path_buf(),
+    );
+    exporter.add_postprocessor(&remove_obsidian_comments);
+    exporter.run().unwrap();
+
+    let expected =
+        read_to_string("tests/testdata/expected/remove-comments/test_comments.md").unwrap();
+    let actual = read_to_string(tmp_dir.path().join(PathBuf::from("test_comments.md"))).unwrap();
+
+    assert_eq!(expected, actual);
+}

tests/testdata/expected/remove-comments/test_comments.md

@@ -0,0 +1,6 @@
+Not a comment
+
+
+````md
+%% Comment in code block should be kept %%
+````

tests/testdata/input/remove-comments/test_comments.md

@@ -0,0 +1,27 @@
+Not a comment
+%% Comment should be removed %%
+```md
+%% Comment in code block should be kept %%
+```
+
+%%
+This is
+a block comment
+that should be removed
+%%
+
+%%
+
+None of the below should be visible in output:
+
+## Header
+
+Code block:
+
+```
+foo
+```
+
+---
+
+%%