gopls/internal/golang: consolidate imports from both file in qualifier

This commit improves qualifier by consolidating imports from both the
main file (x.go) and its corresponding test file (x_test.go).

An imports map is used to track all import paths and their local
renames.  Imports from x_test.go are prioritized over x.go as gopls
is generating test in x_test.go.

This ensures that the generated qualifier correctly reflects any
necessary renames, improving accuracy and consistency.

For golang/vscode-go#1594

Change-Id: I457d5f22f7de4fe86006b57487f243494c8e7f6f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/622320
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Robert Findley <[email protected]>
Auto-Submit: Hongxiang Jiang <[email protected]>

Author: h9jiang

gopls/internal/golang/addtest.go

@@ -17,6 +17,7 @@ import (
 	"html/template"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 
 	"golang.org/x/tools/go/ast/astutil"
@@ -115,6 +116,33 @@ func AddTestForFunc(ctx context.Context, snapshot *cache.Snapshot, loc protocol.
 		return nil, fmt.Errorf("package has type errors: %v", errors[0])
 	}
 
+	// imports is a map from package path to local package name.
+	var imports = make(map[string]string)
+
+	var collectImports = func(file *ast.File) error {
+		for _, spec := range file.Imports {
+			// TODO(hxjiang): support dot imports.
+			if spec.Name != nil && spec.Name.Name == "." {
+				return fmt.Errorf("\"add a test for FUNC\" does not support files containing dot imports")
+			}
+			path, err := strconv.Unquote(spec.Path.Value)
+			if err != nil {
+				return err
+			}
+			if spec.Name != nil && spec.Name.Name != "_" {
+				imports[path] = spec.Name.Name
+			} else {
+				imports[path] = filepath.Base(path)
+			}
+		}
+		return nil
+	}
+
+	// Collect all the imports from the x.go, keep track of the local package name.
+	if err := collectImports(pgf.File); err != nil {
+		return nil, err
+	}
+
 	testBase := strings.TrimSuffix(filepath.Base(loc.URI.Path()), ".go") + "_test.go"
 	goTestFileURI := protocol.URIFromPath(filepath.Join(loc.URI.Dir().Path(), testBase))
 
@@ -192,6 +220,26 @@ func AddTestForFunc(ctx context.Context, snapshot *cache.Snapshot, loc protocol.
 		if err != nil {
 			return nil, err
 		}
+
+		// Collect all the imports from the x_test.go, overwrite the local pakcage
+		// name collected from x.go.
+		if err := collectImports(testPGF.File); err != nil {
+			return nil, err
+		}
+	}
+
+	// qf qualifier returns the local package name need to use in x_test.go by
+	// consulting the consolidated imports map.
+	qf := func(p *types.Package) string {
+		// When generating test in x packages, any type/function defined in the same
+		// x package can emit package name.
+		if !xtest && p == pkg.Types() {
+			return ""
+		}
+		if local, ok := imports[p.Path()]; ok {
+			return local
+		}
+		return p.Name()
 	}
 
 	// TODO(hxjiang): modify existing imports or add new imports.
@@ -231,16 +279,6 @@ func AddTestForFunc(ctx context.Context, snapshot *cache.Snapshot, loc protocol.
 		// the option to drop the return value if the type is unexported.
 	}
 
-	// TODO(hxjiang): qualifier should consolidate existing imports from x
-	// package and existing x_test package. The existing x_test package imports
-	// should overwrite x package imports.
-	var qf types.Qualifier
-	if xtest {
-		qf = (*types.Package).Name
-	} else {
-		qf = typesinternal.NameRelativeTo(pkg.Types())
-	}
-
 	testName, err := testName(fn)
 	if err != nil {
 		return nil, err
@@ -251,7 +289,7 @@ func AddTestForFunc(ctx context.Context, snapshot *cache.Snapshot, loc protocol.
 	}
 
 	if sig.Recv() == nil && xtest {
-		data.PackageName = pkg.Types().Name()
+		data.PackageName = qf(pkg.Types())
 	}
 
 	for i := range sig.Params().Len() {

gopls/internal/test/marker/testdata/codeaction/addtest.txt

@@ -388,3 +388,88 @@ func Foo(in, in1, in2, in3 string) (out, out1, out2 string) {return in, in, in}
 +    }
 +  }
 +}
+-- xpackagerename/xpackagerename.go --
+package main
+
+import (
+  mytime "time"
+  myast "go/ast"
+)
+
+func Foo(t mytime.Time, a *myast.Node) (mytime.Time, *myast.Node) {return t, a} //@codeactionedit("Foo", "source.addTest", xpackage_rename)
+
+-- @xpackage_rename/xpackagerename/xpackagerename_test.go --
+@@ -0,0 +1,26 @@
++package main_test
++
++func TestFoo(t *testing.T) {
++  type args struct {
++    in mytime.Time
++    in2 *myast.Node
++  }
++  tests := []struct {
++    name string // description of this test case
++    args args
++    want mytime.Time
++    want2 *myast.Node
++  }{
++    // TODO: Add test cases.
++  }
++  for _, tt := range tests {
++    got, got2 := main.Foo(tt.args.in, tt.args.in2)
++    // TODO: update the condition below to compare got with tt.want.
++    if true {
++      t.Errorf("%s: Foo() = %v, want %v", tt.name, got, tt.want)
++    }
++    if true {
++      t.Errorf("%s: Foo() = %v, want %v", tt.name, got2, tt.want2)
++    }
++  }
++}
+-- xtestpackagerename/xtestpackagerename.go --
+package main
+
+import (
+  mytime "time"
+  myast "go/ast"
+)
+
+func Foo(t mytime.Time, a *myast.Node) (mytime.Time, *myast.Node) {return t, a} //@codeactionedit("Foo", "source.addTest", xtest_package_rename)
+
+-- xtestpackagerename/xtestpackagerename_test.go --
+package main_test
+
+import (
+  yourtime "time"
+  yourast "go/ast"
+)
+
+var fooTime = yourtime.Time{}
+var fooNode = yourast.Node{}
+
+-- @xtest_package_rename/xtestpackagerename/xtestpackagerename_test.go --
+@@ -11 +11,24 @@
++func TestFoo(t *testing.T) {
++  type args struct {
++    in yourtime.Time
++    in2 *yourast.Node
++  }
++  tests := []struct {
++    name string // description of this test case
++    args args
++    want yourtime.Time
++    want2 *yourast.Node
++  }{
++    // TODO: Add test cases.
++  }
++  for _, tt := range tests {
++    got, got2 := main.Foo(tt.args.in, tt.args.in2)
++    // TODO: update the condition below to compare got with tt.want.
++    if true {
++      t.Errorf("%s: Foo() = %v, want %v", tt.name, got, tt.want)
++    }
++    if true {
++      t.Errorf("%s: Foo() = %v, want %v", tt.name, got2, tt.want2)
++    }
++  }
++}