[gjs: 1/2] Display current line of source code when displaying current frame in debugger

[Philip Chimento <pchimento src gnome org>]

commit 0ca8997eab18ebf37a0e0ee757cc90a93e8a50f3
Author: Nasah Kuma <nasahnash19 gmail com>
Date:   Wed Jan 27 18:16:25 2021 +0000

    Display current line of source code when displaying current frame in debugger

 installed-tests/debugger/down-up.debugger.output |  8 ++++++
 installed-tests/debugger/frame.debugger.output   |  2 ++
 installed-tests/debugger/throw.debugger.output   |  2 ++
 modules/script/_bootstrap/debugger.js            | 33 +++++++++++++-----------
 4 files changed, 30 insertions(+), 15 deletions(-)
---
diff --git a/installed-tests/debugger/down-up.debugger.output 
b/installed-tests/debugger/down-up.debugger.output
index 73f6191d..c8b1a3ba 100644
--- a/installed-tests/debugger/down-up.debugger.output
+++ b/installed-tests/debugger/down-up.debugger.output
@@ -7,21 +7,29 @@ db> down
 Youngest frame selected; you cannot go down.
 db> up
 #1    c() at down-up.debugger.js:12:4
+   12      d();
 db> up
 #2    b() at down-up.debugger.js:8:4
+   8       c();
 db> up
 #3    a() at down-up.debugger.js:4:4
+   4       b();
 db> up
 #4    toplevel at down-up.debugger.js:19:0
+   19  a();
 db> up
 Initial frame selected; you cannot go up.
 db> down
 #3    a() at down-up.debugger.js:4:4
+   4       b();
 db> dn
 #2    b() at down-up.debugger.js:8:4
+   8       c();
 db> dn
 #1    c() at down-up.debugger.js:12:4
+   12      d();
 db> dn
 #0    d() at down-up.debugger.js:16:4
+   16      debugger;
 db> c
 Program exited with code 0
diff --git a/installed-tests/debugger/frame.debugger.output b/installed-tests/debugger/frame.debugger.output
index 25f9df99..9e456cda 100644
--- a/installed-tests/debugger/frame.debugger.output
+++ b/installed-tests/debugger/frame.debugger.output
@@ -5,7 +5,9 @@ db> c
 Debugger statement, b() at frame.debugger.js:8:4
 db> frame 2
 #2    toplevel at frame.debugger.js:11:0
+   11  a();
 db> f 1
 #1    a() at frame.debugger.js:4:4
+   4       b();
 db> c
 Program exited with code 0
diff --git a/installed-tests/debugger/throw.debugger.output b/installed-tests/debugger/throw.debugger.output
index 4e9b5adc..3dd87088 100644
--- a/installed-tests/debugger/throw.debugger.output
+++ b/installed-tests/debugger/throw.debugger.output
@@ -6,6 +6,7 @@ Debugger statement, a() at throw.debugger.js:4:4
 db> throw 'foobar' + 3.14;
 Unwinding due to exception. (Type 'c' to continue unwinding.)
 #0    a() at throw.debugger.js:4:4
+   4       debugger;
 Exception value is:
 $1 = "foobar3.14"
 db> fin
@@ -15,6 +16,7 @@ $2 = "foobar3.14"
 (To rethrow it, type 'throw'.)
 Unwinding due to exception. (Type 'c' to continue unwinding.)
 #0    toplevel at throw.debugger.js:9:4
+   9       a();
 Exception value is:
 $3 = "foobar3.14"
 db> throw
diff --git a/modules/script/_bootstrap/debugger.js b/modules/script/_bootstrap/debugger.js
index 326ec8e9..d1b22ed9 100644
--- a/modules/script/_bootstrap/debugger.js
+++ b/modules/script/_bootstrap/debugger.js
@@ -140,7 +140,7 @@ Debugger.Script.prototype.describeOffset = function describeOffset(offset) {
     return `${url}:${lineNumber}:${columnNumber}`;
 };
 
-function showFrame(f, n, option) {
+function showFrame(f, n, option = {btCommand: false, fullOption: false}) {
     if (f === undefined || f === null) {
         f = focusedFrame;
         if (f === null) {
@@ -153,19 +153,22 @@ function showFrame(f, n, option) {
         if (n === undefined)
             throw new Error('Internal error: frame not on stack');
     }
-    if (!option) {
-        print(`#${n.toString().padEnd(4)} ${f.describeFull()}`);
-    } else {
-        const variables = f.environment.names();
-        print(`#${n.toString().padEnd(4)} ${f.describeFull()}`);
-        for (let i = 0; i < variables.length; i++) {
-            if (variables.length === 0)
-                print('No locals.');
-
-            const value = f.environment.getVariable(variables[i]);
-            const [brief] = debuggeeValueToString(value, {brief: false, pretty: false});
-            print(`${variables[i]} = ${brief}`);
+    print(`#${n.toString().padEnd(4)} ${f.describeFull()}`);
+    if (option.btCommand) {
+        if (option.fullOption) {
+            const variables = f.environment.names();
+            for (let i = 0; i < variables.length; i++) {
+                if (variables.length === 0)
+                    print('No locals.');
+
+                const value = f.environment.getVariable(variables[i]);
+                const [brief] = debuggeeValueToString(value, {brief: false, pretty: false});
+                print(`${variables[i]} = ${brief}`);
+            }
         }
+    } else {
+        let lineNumber = f.line;
+        print(`   ${lineNumber}\t${f.script.source.text.split('\n')[lineNumber - 1]}`);
     }
 }
 
@@ -205,10 +208,10 @@ function backtraceCommand(option) {
         print('No stack.');
     if (option === '') {
         for (let i = 0, f = topFrame; f; i++, f = f.older)
-            showFrame(f, i, false);
+            showFrame(f, i, {btCommand: true, fullOption: false});
     } else if (option === 'full') {
         for (let i = 0, f = topFrame; f; i++, f = f.older)
-            showFrame(f, i, true);
+            showFrame(f, i, {btCommand: true, fullOption: true});
     } else {
         print('Invalid option');
     }