Remove support for GLEAN_TEST_COVERAGE

Author: badboy

CHANGELOG.md

@@ -2,6 +2,9 @@
 
 [Full changelog](https://github.com/mozilla/glean/compare/v67.0.0...main)
 
+* General
+  * Remove support for generating metric testing coverage ([#3397](https://github.com/mozilla/glean/pull/3397))
+
 # v67.0.0 (2026-01-21)
 
 [Full changelog](https://github.com/mozilla/glean/compare/v66.3.0...v67.0.0)

docs/dev/code_coverage.md

@@ -5,7 +5,7 @@
 > which suggests it has a lower chance of containing undetected software bugs compared to a program with low test coverage.
 > ([Wikipedia](https://en.wikipedia.org/wiki/Code_coverage))
 
-This chapter describes how to generate a traditional code coverage report over the Kotlin, Swift and Python code in the Glean SDK repository. To learn how to generate a coverage report about what metrics your project is testing, see the user documentation on [generating testing coverage reports](https://mozilla.github.io/glean/book/user/testing-metrics.html#generating-testing-coverage-reports).
+This chapter describes how to generate a traditional code coverage report over the Kotlin, Swift and Python code in the Glean SDK repository.
 
 ## Generating Kotlin reports locally
 

docs/user/user/metrics/testing-metrics.md

@@ -7,8 +7,6 @@ in any client application it may be used in.
 These functions expose a way to inspect and validate recorded metric values within the client application. but are restricted to test code only.
 (Outside of a testing context, Glean APIs are otherwise write-only so that it can enforce semantics and constraints about data).
 
-To encourage using the testing APIs, it is also possible to [generate testing coverage reports](#generating-testing-coverage-reports) to show which metrics in your project are tested.
-
 ## Example of using the test API
 
 In order to enable metrics testing APIs in each SDK, Glean must be reset and put in testing mode.
@@ -84,53 +82,3 @@ assert 1 == metrics.url.visit.test_get_value()
 </div>
 
 {{#include ../../../shared/tab_footer.md}}
-
-## Generating testing coverage reports
-
-Glean can generate coverage reports to track which metrics are tested in your unit test suite.
-
-There are three steps to integrate it into your continuous integration workflow: recording coverage, post-processing the results, and uploading the results.
-
-### Recording coverage
-
-Glean testing coverage is enabled by setting the `GLEAN_TEST_COVERAGE` environment variable to the name of a file to store results.
-It is good practice to set it to the absolute path to a file, since some testing harnesses (such as `cargo test`) may change the current working directory.
-
-```bash
-GLEAN_TEST_COVERAGE=$(realpath glean_coverage.txt) make test
-```
-
-### Post-processing the results
-
-A post-processing step is required to convert the raw output in the file specified by `GLEAN_TEST_COVERAGE` into usable output for coverage reporting tools. Currently, the only coverage reporting tool supported is [codecov.io](https://codecov.io).
-
-This post-processor is available in the `coverage` subcommand in the [`glean_parser`](https://github.com/mozilla/glean_parser) tool.
-
-For some build systems, `glean_parser` is already installed for you by the build system integration at the following locations:
-
-- On Android/Gradle, `$GRADLE_HOME/glean/bootstrap-4.5.11/Miniconda3/bin/glean_parser`
-- On iOS, `$PROJECT_ROOT/.venv/bin/glean_parser`
-- For other systems, install `glean_parser` using `pip install glean_parser`
-
-The `glean_parser coverage` command requires the following parameters:
-
-  - `-f`: The output format to produce, for example `codecovio` to produce [codecov.io](https://codecov.io)'s custom format.
-  - `-o`: The path to the output file, for example `codecov.json`.
-  - `-c`: The input raw coverage file. `glean_coverage.txt` in the example above.
-  - A list of the `metrics.yaml` files in your repository.
-  
-For example, to produce output for [codecov.io](https://codecov.io):
-
-```bash
-glean_parser coverage -f codecovio -o glean_coverage.json -c glean_coverage.txt app/metrics.yaml
-```
-
-In this example, the `glean_coverage.json` file is now ready for uploading to codecov.io.
-
-### Uploading coverage
-
-If using `codecov.io`, the uploader doesn't send coverage results for YAML files by default. Pass the `-X yaml` option to the uploader to make sure they are included:
-
-```bash
-bash <(curl -s https://codecov.io/bash) -X yaml
-```

glean-core/src/coverage.rs

@@ -21,7 +21,6 @@ use serde::{Deserialize, Serialize};
 use serde_json::{json, Value as JsonValue};
 
 use crate::common_metric_data::CommonMetricDataInternal;
-use crate::coverage::record_coverage;
 use crate::error_recording::{record_error, ErrorType};
 use crate::metrics::{DatetimeMetric, TimeUnit};
 use crate::storage::INTERNAL_STORAGE;
@@ -684,8 +683,6 @@ impl EventDatabase {
         meta: &'a CommonMetricDataInternal,
         store_name: &str,
     ) -> Option<Vec<RecordedEvent>> {
-        record_coverage(&meta.base_identifier());
-
         let value: Vec<RecordedEvent> = self
             .event_stores
             .read()

glean-core/src/event_database/mod.rs

@@ -35,7 +35,6 @@ use metrics::RemoteSettingsConfig;
 mod common_metric_data;
 mod core;
 mod core_metrics;
-mod coverage;
 mod database;
 mod debug;
 #[cfg(feature = "benchmark")]

glean-core/src/lib.rs

@@ -89,7 +89,7 @@ impl BooleanMetric {
     pub fn get_value(&self, glean: &Glean, ping_name: Option<&str>) -> Option<bool> {
         let queried_ping_name = ping_name.unwrap_or_else(|| &self.meta().inner.send_in_pings[0]);
 
-        match StorageManager.snapshot_metric_for_test(
+        match StorageManager.snapshot_metric(
             glean.storage(),
             queried_ping_name,
             &self.meta.identifier(glean),

glean-core/src/metrics/boolean.rs

@@ -126,7 +126,7 @@ impl CounterMetric {
             .into()
             .unwrap_or_else(|| &self.meta().inner.send_in_pings[0]);
 
-        match StorageManager.snapshot_metric_for_test(
+        match StorageManager.snapshot_metric(
             glean.storage(),
             queried_ping_name,
             &self.meta.identifier(glean),

glean-core/src/metrics/counter.rs

@@ -218,7 +218,7 @@ impl CustomDistributionMetric {
             .into()
             .unwrap_or_else(|| &self.meta().inner.send_in_pings[0]);
 
-        match StorageManager.snapshot_metric_for_test(
+        match StorageManager.snapshot_metric(
             glean.storage(),
             queried_ping_name,
             &self.meta.identifier(glean),

glean-core/src/metrics/custom_distribution.rs

@@ -96,7 +96,7 @@ impl DenominatorMetric {
             .into()
             .unwrap_or_else(|| &self.meta().inner.send_in_pings[0]);
 
-        match StorageManager.snapshot_metric_for_test(
+        match StorageManager.snapshot_metric(
             glean.storage(),
             queried_ping_name,
             &self.meta().identifier(glean),