Code block: move instructions retrieval to a separate function

Not only is it cleaner and more testable, but it allows for other
functions to also retrieve instructions.

2 files changed, 37 insertions, 26 deletions

diff --git a/bot/cogs/codeblock/cog.py b/bot/cogs/codeblock/cog.py
index 396353d40..23d5267a9 100644
--- a/bot/cogs/codeblock/cog.py
+++ b/bot/cogs/codeblock/cog.py
@@ -8,7 +8,8 @@ from discord.ext.commands import Bot, Cog
 from bot.cogs.token_remover import TokenRemover
 from bot.constants import Categories, Channels, DEBUG_MODE
 from bot.utils.messages import wait_for_deletion
-from . import instructions, parsing
+from . import parsing
+from .instructions import get_instructions
 
 log = logging.getLogger(__name__)
 
@@ -120,31 +121,10 @@ class CodeBlockCog(Cog, name="Code Block"):
             log.trace(f"Skipping code block detection of {msg.id}: #{msg.channel} is on cooldown.")
             return
 
-        blocks = parsing.find_code_blocks(msg.content)
-        if blocks is None:
-            # None is returned when there's at least one valid block with a language.
-            return
-        if not blocks:
-            log.trace(f"No code blocks were found in message {msg.id}.")
-            description = instructions.get_no_ticks_message(msg.content)
-        else:
-            log.trace("Searching results for a code block with invalid ticks.")
-            block = next((block for block in blocks if block.tick != parsing.BACKTICK), None)
-
-            if block:
-                log.trace(f"A code block exists in {msg.id} but has invalid ticks.")
-                description = instructions.get_bad_ticks_message(block)
-            else:
-                log.trace(f"A code block exists in {msg.id} but is missing a language.")
-                block = blocks[0]
-
-                # Check for a bad language first to avoid parsing content into an AST.
-                description = instructions.get_bad_lang_message(block.content)
-                if not description:
-                    description = instructions.get_no_lang_message(block.content)
-
-        if description:
-            await self.send_guide_embed(msg, description)
+        instructions = get_instructions(msg.content)
+        if instructions:
+            await self.send_guide_embed(msg, instructions)
+
             if msg.channel.id not in self.channel_whitelist:
                 log.trace(f"Adding #{msg.channel} to the channel cooldowns.")
                 self.channel_cooldowns[msg.channel.id] = time.time()
diff --git a/bot/cogs/codeblock/instructions.py b/bot/cogs/codeblock/instructions.py
index 28242ce75..d331dd2ee 100644
--- a/bot/cogs/codeblock/instructions.py
+++ b/bot/cogs/codeblock/instructions.py
@@ -133,3 +133,34 @@ def get_no_lang_message(content: str) -> Optional[str]:
         )
     else:
         log.trace("Aborting missing language instructions: content is not Python code.")
+
+
+def get_instructions(content: str) -> Optional[str]:
+    """Return code block formatting instructions for `content` or None if nothing's wrong."""
+    log.trace("Getting formatting instructions.")
+
+    blocks = parsing.find_code_blocks(content)
+    if blocks is None:
+        log.trace("At least one valid code block found; no instructions to return.")
+        return
+
+    if not blocks:
+        log.trace(f"No code blocks were found in message.")
+        return get_no_ticks_message(content)
+    else:
+        log.trace("Searching results for a code block with invalid ticks.")
+        block = next((block for block in blocks if block.tick != parsing.BACKTICK), None)
+
+        if block:
+            log.trace(f"A code block exists but has invalid ticks.")
+            return get_bad_ticks_message(block)
+        else:
+            log.trace(f"A code block exists but is missing a language.")
+            block = blocks[0]
+
+            # Check for a bad language first to avoid parsing content into an AST.
+            description = get_bad_lang_message(block.content)
+            if not description:
+                description = get_no_lang_message(block.content)
+
+            return description