Silver Dollar

Eucalyptus Cinerea, a.k.a. The Silver Dollar Gum, is a species of gum tree known for being particularly small and compact

Overview

The practice of spamdexing is alive and well on gumtree.com.au, with unscrupulous sellers able to manipulate search results by adding a serious of keyword "tags" at the end of their description.

This appears to be especially egregious from car dealerships, and so searching for a specific make of car often requires wading through a huge number of entirely unrelated listings.

This extension aims to resolve that by detecting and highlighting these suspect results, leaving the user free to concentrate on what they're actually looking for.

How it works

As each page loads, the extension will parse the contents and determine whether the listing matches the search. It does this by considering the title against each word in the search query, using fuzzy logic to allow imperfect matches.

If a listing fails to meet the required match threshold, rather than being removed entirely it will be rendered mostly transparent. This allows the user to easily skim past these listings, while still allowing them to be viewed if desired.

Here's an example (note that this screenshot has had some identifying features from both result sets blurred for privacy).

Settings

• Enabled - Used to entirely disable the extension
• Transparency - Adjusts the level of transparency that filtered-out listings will be rendered as. Goes from 0 (fully opaque) to 100 (fully transparent)
• Fuzziness - Used to modify the fuzzy logic threshold for determining whether a listing matches the search query. Higher values increase the chance of a positive match. Note that having some fuzziness allows for small differences like casing, hyphens instead of spaces, minor spelling errors, etc.
• Title Only - Whether to only consider the listing title when matching, or whether to also include the reduced description that's present on the search results page. If the latter, note that listings that include the spam tags towards the top of their description will likely have them present here, leading to false positives.

Development

This extension is written in typescript, using webpack to bundle it for deployment. There are three deployable output scripts:

• bundle.js - the main extension
• popup.js - the settings popup
• browser-polyfill.js - a webextension-specific polyfill

To package the extension, run the script at ./scripts/build.sh. By default the package will be in development mode: to run as production set the environment variable DEPLOYMENT_MODE=production.

Some notable npm scripts:

• prettier:check and prettier:write - run prettifying checks, with or without automatic fixes.
• lint - run linting
• test and test:coverage - run unit tests, with or without a coverage report
• pre-push - run prettier and lint in sequence. This is run as a hook on git push

TODO:

• Improve efficiency by restricting the acted-on URL to only search pages
• Utilise github actions to automatically create releases
• Improve logging using a proper logger and better standards