Improve & reduce golang parsing utility.

This removes the listing parsing functions for specific types of listings, because it can all be done with one function even when the listings are monotyped. Mixed listings are very common endpoints on Reddit.
turnage · Oct 29, 2015 · 8b9bd66 · 8b9bd66
1 parent 601aa8e
commit 8b9bd66
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Showing 3 changed files with 25 additions and 121 deletions.
diff --git a/parser.go b/parser.go
@@ -36,43 +36,6 @@ func ParseComment(raw json.RawMessage) (*Comment, error) {
 	return comment, nil
 }
 
-// ParseLinkListing parses a JSON message expected to be a listing of Links
-// (Link is the Reddit type for what may also be called posts or submissions).
-// Links do not have a comments field except when fetched from their own
-// comments page; the Links returned from this function have no comments
-// included.
-func ParseLinkListing(raw json.RawMessage) ([]*Link, error) {
-	thing, err := handleThing(raw)
-	if err != nil {
-		return nil, err
-	}
-
-	buffer, ok := thing.(*listingBuffer)
-	if !ok {
-		return nil, fmt.Errorf("JSON message was not a listing")
-	}
-
-	return buffer.links, nil
-}
-
-// ParseMessageListing parses a JSON message expected to be a listing of
-// Messages (e.g. an inbox JSON digest). Reddit will provide comments as
-// Messages if viewed from the inbox--use GetWasComment() to identify the
-// original type.
-func ParseMessageListing(raw json.RawMessage) ([]*Message, error) {
-	thing, err := handleThing(raw)
-	if err != nil {
-		return nil, err
-	}
-
-	buffer, ok := thing.(*listingBuffer)
-	if !ok {
-		return nil, fmt.Errorf("JSON message was not a listing")
-	}
-
-	return buffer.messages, nil
-}
-
 // ParseThread parses a JSON message expected to represent a Link comment page.
 func ParseThread(raw json.RawMessage) (*Link, error) {
 	// The JSON message should be a top level array, holding the link in the
@@ -126,20 +89,25 @@ func ParseThread(raw json.RawMessage) (*Link, error) {
 	return link, nil
 }
 
-// ParseComboListing parses a JSON message expected to be a listing with a mix
-// of comments and posts (e.g. a user landing page).
-func ParseComboListing(raw json.RawMessage) ([]*Link, []*Comment, error) {
+// ParseListing parses a JSON message expected to be a listing with any mix of
+// Links, Comments, or Messages.
+func ParseListing(raw json.RawMessage) (
+	[]*Link,
+	[]*Comment,
+	[]*Message,
+	error,
+) {
 	thing, err := handleThing(raw)
 	if err != nil {
-		return nil, nil, err
+		return nil, nil, nil, err
 	}
 
 	buffer, ok := thing.(*listingBuffer)
 	if !ok {
-		return nil, nil, fmt.Errorf("JSON message was nonlisting")
+		return nil, nil, nil, fmt.Errorf("JSON message was nonlisting")
 	}
 
-	return buffer.links, buffer.comments, nil
+	return buffer.links, buffer.comments, buffer.messages, nil
 }
 
 // handleThing unmarshals Things and parses them.

diff --git a/parser_test.go b/parser_test.go
@@ -60,80 +60,6 @@ func TestParseComment(t *testing.T) {
 	}
 }
 
-func TestParseLinkListing(t *testing.T) {
-	listing, err := ParseLinkListing([]byte(
-		`{
-			"kind": "Listing",
-			"data": {
-				"children": [
-					{
-						"kind": "t3",
-						"data": {
-							"title": "1"
-						}
-					},
-					{
-						"kind": "t3",
-						"data": {
-							"title": "2"
-						}
-					},
-					{
-						"kind": "t3",
-						"data": {
-							"title": "3"
-						}
-					}
-				]
-			}
-		}`))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if len(listing) != 3 {
-		t.Fatalf("got %d links; wanted 3", len(listing))
-	}
-
-	if listing[2].GetTitle() != "3" {
-		t.Errorf("got %s as title; wanted 3", listing[2].GetTitle())
-	}
-}
-
-func TestParseMessageListing(t *testing.T) {
-	listing, err := ParseMessageListing([]byte(
-		`{
-			"kind": "Listing",
-			"data": {
-				"children": [
-					{
-						"kind": "t4",
-						"data": {
-							"body": "1"
-						}
-					},
-					{
-						"kind": "t4",
-						"data": {
-							"body": "2"
-						}
-					}
-				]
-			}
-		}`))
-	if err != nil {
-		t.Fatal(err)
-	}
-
-	if len(listing) != 2 {
-		t.Fatalf("got %d messages; wanted 2", len(listing))
-	}
-
-	if listing[1].GetBody() != "2" {
-		t.Errorf("got %s as body; wanted 2", listing[1].GetBody())
-	}
-}
-
 func TestParseThread(t *testing.T) {
 	link, err := ParseThread([]byte(
 		`[
@@ -183,8 +109,8 @@ func TestParseThread(t *testing.T) {
 	}
 }
 
-func TestParseComboListing(t *testing.T) {
-	links, comments, err := ParseComboListing([]byte(
+func TestParseListing(t *testing.T) {
+	links, comments, messages, err := ParseListing([]byte(
 		`{
 			"kind": "Listing",
 			"data": {
@@ -200,6 +126,12 @@ func TestParseComboListing(t *testing.T) {
 						"data": {
 							"body": "1"
 						}
+					},
+					{
+						"kind": "t4",
+						"data": {
+							"body": "1"
+						}
 					}
 				]
 			}
@@ -215,4 +147,7 @@ func TestParseComboListing(t *testing.T) {
 	if len(comments) != 1 {
 		t.Errorf("got %d comments; wanted 1", len(comments))
 	}
+	if len(messages) != 1 {
+		t.Errorf("got %d messages; wanted 1", len(messages))
+	}
 }
diff --git a/readme.md b/readme.md
@@ -23,8 +23,9 @@ See ````protoc --help```` for further guidance.
 No breaking changes will be made to redditproto messages as of version 1.0. Any
 message changes will be noted here in the readme.
 
-* 0.9 -> August 25th, 2015
-* 1.0 -> October 21st, 2015
+* 0.9.0 -> August 25th, 2015
+* 1.0.0 -> October 21st, 2015
+* 2.0.0 -> Octover 29th, 2015 (No message changes; improve Go utilities).
 
 # Gophers