fix(routing/http): avoid escaping comma separator

The comma is in the "sub-delims" set of characters that don't need to be
encoded in most parts of a URL, including query parameters. Golang
standard library percent-escapes it for consistency, but we prefer
human-readable /routing/v1 URLs, and real comma is restored here to
ensure human and machine requests hit the same HTTP cache keys.

CHANGELOG.md

@@ -22,6 +22,8 @@ The following emojis are used to highlight certain changes:
 
 ### Fixed
 
+- `routing/http/client`: optional address and protocol filter parameters from [IPIP-484](https:/ipfs/specs/pull/484) use human-readable `,` instead of `%2C`. [#688](https:/ipfs/boxo/pull/688)
+
 ### Security
 
 ## [v0.24.0]

routing/http/filters/filters.go

@@ -39,7 +39,13 @@ func AddFiltersToURL(baseURL string, protocolFilter, addrFilter []string) string
  query.Set("filter-addrs", strings.Join(addrFilter, ","))
  }
 
- parsedURL.RawQuery = query.Encode()
+ // The comma is in the "sub-delims" set of characters that don't need to be
+ // encoded in most parts of a URL, including query parameters. Golang
+ // standard library percent-escapes it for consistency, but we prefer
+ // human-readable /routing/v1 URLs, and real comma is restored here to
+ // ensure human and machine requests hit the same HTTP cache keys.
+ parsedURL.RawQuery = strings.ReplaceAll(query.Encode(), "%2C", ",")
+
  return parsedURL.String()
 }
 

routing/http/filters/filters_test.go

@@ -30,21 +30,21 @@ func TestAddFiltersToURL(t *testing.T) {
  baseURL: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi",
  protocolFilter: []string{"transport-bitswap", "transport-ipfs-gateway-http"},
  addrFilter: nil,
- expected: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi?filter-protocols=transport-bitswap%2Ctransport-ipfs-gateway-http",
+ expected: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi?filter-protocols=transport-bitswap,transport-ipfs-gateway-http",
  },
  {
  name: "Only addr filter",
  baseURL: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi",
  protocolFilter: nil,
  addrFilter: []string{"ip4", "ip6"},
- expected: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi?filter-addrs=ip4%2Cip6",
+ expected: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi?filter-addrs=ip4,ip6",
  },
  {
  name: "Both filters",
  baseURL: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi",
  protocolFilter: []string{"transport-bitswap", "transport-graphsync-filecoinv1"},
  addrFilter: []string{"ip4", "ip6"},
- expected: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi?filter-addrs=ip4%2Cip6&filter-protocols=transport-bitswap%2Ctransport-graphsync-filecoinv1",
+ expected: "https://example.com/routing/v1/providers/bafybeigdyrzt5sfp7udm7hu76uh7y26nf3efuylqabf3oclgtqy55fbzdi?filter-addrs=ip4,ip6&filter-protocols=transport-bitswap,transport-graphsync-filecoinv1",
  },
  {
  name: "URL with existing query parameters",