feat: Replace timespan report with trending report

README.md

@@ -108,6 +108,12 @@ To run only a specific module:
 ./dashboard.sh --format html hackernews
 ```
 
+To run a specific reporter:
+
+- **`top-stars`**: Shows the top 10 repositories by stars.
+- **`trending`**: Shows the change in metrics over a given timespan. Only shows metrics that have changed.
+  - Usage: `./dashboard.sh -r trending [days]`
+
 ## Configuration
 
 All configuration is done in the `config/config.sh` file.

dashboard.sh

@@ -260,7 +260,7 @@ else
 
                     if ($5 == "null") {
                         printf "{\"date\":\"%s\",\"module\":\"%s\",\"channels\":\"%s\",\"namespace\":\"%s\",\"value\":null}", $1, $2, $3, $4
-                    } else if ($5 ~ /^[0-9]+$/) {
+                    } else if ($5 != "" && $5 == $5+0) {
                         printf "{\"date\":\"%s\",\"module\":\"%s\",\"channels\":\"%s\",\"namespace\":\"%s\",\"value\":%s}", $1, $2, $3, $4, $5
                     } else {
                         printf "{\"date\":\"%s\",\"module\":\"%s\",\"channels\":\"%s\",\"namespace\":\"%s\",\"value\":\"%s\"}", $1, $2, $3, $4, $5

docs/dashboard-reporters.md

@@ -26,14 +26,14 @@ Some reporters accept their own arguments, which you can pass after the reporter
 
 Here is a list of the currently available reporters.
 
-### `timespan`
+### `trending`
 
-The `timespan` reporter shows the change in each metric over a period of time. It reads all the `.tsv` report files from the `reports/` directory and calculates the difference between the first and last recorded values for each metric.
+The `trending` reporter shows the change in each metric over a period of time, but it only includes metrics that have actually changed. It reads all the `.tsv` report files from the `reports/` directory and calculates the difference between the first and last recorded values for each metric, filtering out any that have a change of zero.
 
 **Usage:**
 
 ```bash
-./dashboard.sh -r timespan [days]
+./dashboard.sh -r trending [days]
 ```
 
 - **`[days]`** (optional): The number of days of history to analyze.
@@ -43,8 +43,6 @@ The `timespan` reporter shows the change in each metric over a period of time. I
 - If `[days]` is not provided, it will analyze all reports in your `reports/` directory to show the all-time change.
 - If `[days]` is provided, it will show the change over the last `N` days.
 
-**Note on `[days]` filtering:** This feature is currently not working as expected due to limitations in the `date` command of the execution environment. The script is unable to parse dates from the report filenames reliably. At present, the `timespan` reporter will always show the all-time history regardless of this argument.
-
 ### `top-stars`
 
 The `top-stars` reporter finds the most recent report file and lists the top repositories by their star count.

reporters/timespan.sh → reporters/trending.sh

@@ -1,9 +1,10 @@
 #!/usr/bin/env bash
 
-# reporters/timespan.sh
+# reporters/trending.sh
 #
-# Shows the change in metrics over a given timespan.
-# Usage: ./dashboard.sh -r timespan [days]
+# Shows the trending metrics over a given timespan.
+# Only shows metrics that have changed.
+# Usage: ./dashboard.sh -r trending [days]
 #
 # If [days] is provided, it shows the change over the last N days.
 # If not, it shows the change over all available history.
@@ -36,9 +37,12 @@ if [ -n "$DAYS_AGO" ]; then
     CUTOFF_DATE=$(date -d "$DAYS_AGO days ago" +%s)
     for file in "${ALL_FILES[@]}"; do
         FILENAME=$(basename "$file" .tsv)
-        # The filename is a timestamp. It can be in various formats.
-        # We normalize it to a format that `date -d` can handle.
-        FILENAME_FOR_DATE=$(echo "$FILENAME" | sed 's/_/T/')
+        # The filename is a timestamp in the format YYYY-MM-DDTHH-MM-SSZ.
+        # We normalize it to 'YYYY-MM-DD HH:MM:SS' so that `date -d` can parse it.
+        DATE_PART=$(echo "$FILENAME" | cut -d'T' -f1)
+        TIME_PART=$(echo "$FILENAME" | cut -d'T' -f2 | sed 's/Z$//')
+        TIME_PART_COLONS=$(echo "$TIME_PART" | tr '-' ':')
+        FILENAME_FOR_DATE="$DATE_PART $TIME_PART_COLONS"
         FILE_DATE=$(date -d "$FILENAME_FOR_DATE" +%s 2>/dev/null)
 
         if [ -z "$FILE_DATE" ]; then
@@ -80,12 +84,14 @@ FNR == 1 { next; } # Skip header row of each file
 END {
     for (metric in last_value) {
         change = last_value[metric] - first_value[metric];
-        # Add a plus sign for positive changes
-        if (change > 0) {
-            change_str = "+" change;
-        } else {
-            change_str = change;
+        if (change != 0) {
+            # Add a plus sign for positive changes
+            if (change > 0) {
+                change_str = "+" change;
+            } else {
+                change_str = change;
+            }
+            print metric, first_value[metric], last_value[metric], change_str;
         }
-        print metric, first_value[metric], last_value[metric], change_str;
     }
 }' "${TARGET_FILES[@]}"