fix: Removed exports over-tainting all importers

CHANGELOG.md

@@ -5,6 +5,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.25.2] - 2026-08-07
+
+### Fixed
+- Removing an unused export no longer floods every importer with taint. A deleted symbol was logged but never recorded as a change, so the per-file AST diff returned *no affected symbols* — and in the fine-grained path (`FindAffectedFiles`) an empty diff falls through to tainting the **whole file** with `*`. Deleting one unused export from a widely-imported helper (e.g. `ERROR_MESSAGE` from `gdc-ldm-modeler-e2e`'s `playwright/helpers/selectors.ts`) therefore tainted every file that imported it, flagging all ~48 dependent specs. Deleted symbols are now recorded as changed and propagate by name, so a removed export taints exactly the files that imported *that* symbol: an unused one taints nobody, while a removed *used* export still flags its importers (no false negative). The deleted names are appended after intra-file propagation (which walks only surviving symbols) and before the whole-file side-effect fallback, so a deletion-only change is carried precisely instead of being widened.
+
 ## [0.25.1] - 2026-08-07
 
 ### Fixed
@@ -397,6 +402,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Multi-stage Docker build
 - Automated vendor upgrade workflow
 
+[0.25.2]: https://github.com/gooddata/gooddata-goodchanges/compare/v0.25.1...v0.25.2
 [0.25.1]: https://github.com/gooddata/gooddata-goodchanges/compare/v0.25.0...v0.25.1
 [0.25.0]: https://github.com/gooddata/gooddata-goodchanges/compare/v0.24.13...v0.25.0
 [0.24.13]: https://github.com/gooddata/gooddata-goodchanges/compare/v0.24.12...v0.24.13

VERSION

@@ -1 +1 @@
-0.25.1
+0.25.2

internal/analyzer/astdiff.go

@@ -107,16 +107,27 @@ func findAffectedSymbolsByASTDiff(oldAnalysis *tsparse.FileAnalysis, newAnalysis
 		affected = append(affected, sym.Name)
 	}
 
-	// Log deleted symbols (in old but not in new)
+	// Deleted symbols (in old but not in new) are themselves a change: removing an
+	// export can break whoever imported it, so record the deleted names and let
+	// them propagate to importers. This keeps detection precise — a removed
+	// *unused* export taints nobody, instead of the empty-diff falling through to a
+	// whole-file taint downstream. Type-only deletions are ignored unless includeTypes.
+	var deleted []string
 	if oldAnalysis != nil {
 		newSymbolNames := make(map[string]bool)
 		for _, sym := range newAnalysis.Symbols {
 			newSymbolNames[sym.Name] = true
 		}
 		for _, sym := range oldAnalysis.Symbols {
-			if !newSymbolNames[sym.Name] {
-				log.Debugf("    %s: DELETED symbol", sym.Name)
+			if newSymbolNames[sym.Name] {
+				continue
 			}
+			if sym.IsTypeOnly && !includeTypes {
+				log.Debugf("    %s: DELETED type-only symbol (skipped, includeTypes=false)", sym.Name)
+				continue
+			}
+			log.Debugf("    %s: DELETED symbol", sym.Name)
+			deleted = append(deleted, sym.Name)
 		}
 	}
 
@@ -188,6 +199,12 @@ func findAffectedSymbolsByASTDiff(oldAnalysis *tsparse.FileAnalysis, newAnalysis
 		}
 	}
 
+	// Removed symbols propagate to whoever imported them. Appended after the
+	// intra-file rebuild (which only walks NEW symbols and would drop them) and
+	// before the fallback below, so a change that is purely a deletion is carried
+	// by these names rather than misrouted into a whole-file side-effect taint.
+	affected = append(affected, deleted...)
+
 	// Fallback: if no symbols were detected but the file clearly changed,
 	// check if changes are outside any symbol (e.g. top-level side effects,
 	// copyright comments). If there are runtime side-effect changes, taint all symbols.