From f5d2d30f5bb13a673ca279b66572231458924a61 Mon Sep 17 00:00:00 2001
From: Douglas Eichelberger <dduugg@gmail.com>
Date: Mon, 3 Feb 2025 06:40:13 -0800
Subject: [PATCH] Add test for concurrent fetching

---
 Library/Homebrew/test/cmd/fetch_spec.rb       |  22 ++++++++++++++++++
 .../fixtures/tarballs/testball2-0.1-linux.tbz | Bin 0 -> 3253 bytes
 .../tarballs/testball2-0.1-patches.tgz        | Bin 0 -> 368 bytes
 .../fixtures/tarballs/testball2-0.1.tbz       | Bin 0 -> 1318 bytes
 .../spec/shared_context/integration_test.rb   |   6 +++--
 5 files changed, 26 insertions(+), 2 deletions(-)
 create mode 100644 Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1-linux.tbz
 create mode 100644 Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1-patches.tgz
 create mode 100644 Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1.tbz

diff --git a/Library/Homebrew/test/cmd/fetch_spec.rb b/Library/Homebrew/test/cmd/fetch_spec.rb
index 7b0cc3de7a..c264a66147 100644
--- a/Library/Homebrew/test/cmd/fetch_spec.rb
+++ b/Library/Homebrew/test/cmd/fetch_spec.rb
@@ -14,4 +14,26 @@ RSpec.describe Homebrew::Cmd::FetchCmd do
     expect(HOMEBREW_CACHE/"testball--0.1.tbz").to be_a_symlink
     expect(HOMEBREW_CACHE/"testball--0.1.tbz").to exist
   end
+
+  it "concurrently downloads formula URLs", :integration_test do
+    setup_test_formula "testball1"
+    setup_test_formula "testball2"
+
+    expect { brew "fetch", "testball1", "testball2", "--concurrency=2" }.to be_a_success
+
+    expect(HOMEBREW_CACHE/"testball1--0.1.tbz").to be_a_symlink
+    expect(HOMEBREW_CACHE/"testball1--0.1.tbz").to exist
+    expect(HOMEBREW_CACHE/"testball2--0.1.tbz").to be_a_symlink
+    expect(HOMEBREW_CACHE/"testball2--0.1.tbz").to exist
+  end
+
+  it "errors when concurrently downloading to the same destination", :integration_test do
+    # This test will fail if the fetch is not performed concurrently.
+    # N.B. this test relies on how we set up test formulae, see the `integration_test` shared context.
+    setup_test_formula "testball1"
+    setup_test_formula "testball3"
+
+    expect { brew "fetch", "testball1", "testball3", "--concurrency=2" }.to be_a_failure
+      .and output(/Error:.*process has already locked/).to_stderr
+  end
 end
diff --git a/Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1-linux.tbz b/Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1-linux.tbz
new file mode 100644
index 0000000000000000000000000000000000000000..5ca2be071ffdf1e8ea0ac84e7de32eaaa1025bb6
GIT binary patch
literal 3253
zcmV;m3`+AtT4*^jL0KkKS?o(-z5o;YfB*mg|NsB@|NsC0|L_0z|NifP*fd8(RP+6?
z^2~PsZ~x#A9{>OV000000000000000L7->`L6B$~28>LN13(5K13<zWGz|a%05k?h
zjQ{`u0MU_?CMJMn(TFq+0LU^813=M<k)UV*!~kd*Lq>t1000Jn$kCtx000^?GGxTi
z44N?pfuI=%L7-?FF)}m_02qJ`0|;o)Gynhq&>0#u00003Mn+7SngNqWAkZ`eAjmWg
z14brBfuI8r0ia<G8U}y>02%`$Mt}eS0BFd`lM_HPXv7)@fMgj4fuLx_$j~$ZVgNJ@
zA)`Rh0009(WN6R;000dc88TvM22B_hL_kTCAOM(#iK*l=H8gsdr=uj(WKHOh$?25!
zH1x@#l=VF{A%>BZdU}~2rly$0(W44_o7A2SPfaQ5Hkz4}O))l;_FSZ}Ug<d8Zz=8H
z)Qkyxrjx>6m#k6WD2k;dl9YY*9)rzLu`AM`l%i6UkNc$&6j4PI*HK2gQrJt0!f`fK
zZZ_Mjg7u77B}A&yM5w`4iB%<4b5}H%xyl`iQG=`{id-jRy++&CsBttbV#U#DQPE&3
z%GGpPj}6AxHCpV98jKq&4sub}E>W!AZLDcDH(Kf}ZL>Fvml_x_bCQeFu|%y^Muin~
z*cEhM!P%<RYN(ezF1dn??)|LL<}PCCtwy_5W8|_feny52%U7{EiAp8PNkmFSr4}NO
zHLTupn6ZDm)2?$Imt^FyM{JXl<}@6o6j-WOD2gJl%rZ4lHIQ$kWz;1tWVH)dE@pnz
zLrK8$o=wD0D~_JG$*mQfk?a#GUdop$C7B9QF`3ZIP}NL9b<S&~{&&lK=huIW%zyRf
zKb7*IA?3P9-gBLU=&*j<sPkWK;<nHZgN3@&bY7`qELx+D*|;71`C3R3+%I+MdQ`ny
zRdpVr?wXFtkq|_5+KMId*1nTSw1mH5l~qXlE|KmQ9s*F<T<((ls{}{6N)SBMzOq8r
zciUAQPI`+P6oh`0^wfDPAE>HX7pz$3tWp*w#KrLzz3SMA+Djt^5gqI7sP-<k*uHAW
zwSv}WD@gw|=1fFGP4E;U6-pq7IVeDlq>&zxC=nf0N+D_`!b*sgN>UR9N=Zsme;Q&U
zI*EuwpqPY2SeL&_i9ygw1bkvhwJ0|dfofKz5fKuU5fLdsl!uCxQ6f@8T!v?g(@UPU
zbK0bcTB?LfL=uriQIMiakr72yLiH3hk|K?yQ50oS1gN1DQA3GUQb|=5TH{eG9?-Q_
ziCGAuPZ{1Qhq3KC=f3ILH21S{-xBaqFER3+``0^HjH1<#nydOAssEL)YVVi6QpOA)
z&bZTBu}5~}YBo^~w!}=#ZS7ZXe5spdTGy)!(wK(xD}~i%B&)1@<rfm^v?!IzL`Pti
z?+rt&N+@7b79_D^iX@@oy9Wb_y2zt-R=bVYu5w%pm3HZ6UgKiU)JhtW51RFAv1VF|
zwo+zTqkV4+mZw!{>r!-C6qj~(&J~XElYu8-O7x-OlN^#^Rs+aY5eph>JeT81FI3FX
zjn|}Jl)l@f<+L$E(Sk;W%CK07dRGIM^)Bi3-Fwe|`^$ZI!hKiuySK$&{>RRICbMBE
zhWbQRD2U@E9aM#+f?U?C(<9xgwTk5%$x$zgs#GJaN;{Q@o~j+<NAe^e4cVxO?+HXb
zVogSdhN2{@s;a81A5r6|h;tiHc<Qfp7a}_3qBh;juR#?e2aJ;C?20PL(rGPRu~e>F
zs@1DjE<U5OQ3yR0iyH11141K^)k5;AN>O@7qD|DIF_)-fs!#TIkMeXMVMUA=uXG)Y
z&wZEPdvjs1$k!x!?7o8*M{dZqRf?j86k4%s?L4RQI;|#}QKpl5DkTgXY8_*JM{w3&
zqE$;yB8sA_4r*R=GckcKAw}zoB`9>(kyWqHNk>)d)L_7&MG7O{9}OFi-e6`bUdoqv
z#C^oO#GwqYi9ze-=YL%t-oMPU##FvqNQZv^)9ybi!ZW1>?gbjjYAE{7*s;d)7L_hY
zgWD?Qy@T8qq4LRmH4o8A-m0QsMdT&@%#4hNby-zPtzy-z$y}jDRZ3F)^3|j1r1nqr
zd1{N1C+R+7S)W<hzJlgb*ELrPM)F=cMarY@I|pQDZ8lyjQDVjlD(+J3)hty+c*#Xr
zx`}GF)*?R3sG=IFN=Wn)Y9*}TQ4ZBr57%JTRp2dA9m7pjMNvehEUK!ar)tX3iyJH#
zLKrYnuGC(l<pqmasIe&C8W{|W*b-cgW2B;7!*(HJsZmB(Iw4bq=CDV-+EN~&@1M7{
z@XNl3x%G<L#p|E=pE0)6>o#5Maf|zxx0X2v>aIAJsI^7Pqs7qPY0>FA*V6i|jW*{O
za?r8CyAbUkQLwqJ)@+(09}yloDCD>trVY5oL)Rq+bgz^?i7Kp73>u0fuPDdj^9t6!
zY{HRqiSSpJug+1n<u6MIsdCY;u@McJh~Z8P)R)~-B8(sWh+wdYeTOgW@l*Uhhn+pH
zSPW4Nl!#FfqxiXW+1CCl*oy3R$3=!Vwc-?wB;zxrq^2tb_H{h8R+5NmEM~{!qarDC
z{p91FnO0^_-pg%Rr3`7Cq{?Nv841G`Xk#-r#gU~m7i6S;hLMqeF&Qdwtt*ib$u}zs
zB5_!z3h831E!2!Jj270^T;OAU_}?q+n`0Ux6rv?{I!RpOQ6?=_Rct7+BZc@~$>BFl
z&YRi4J7emynr!W?@7_z+KVtWY_{&a7iqR=3qEh9eN+_`^mMlt%QAHF*R9KZC9oj5r
zSh*;ay=wLXNUAJG3M#!-7p)!=^;Z_8%$~{SIp*Tkt%tF5Uoqf5N#Z=`TIsSq2lgfQ
zo`U7CXz$c=+m7+T?A@w7GvKJX(0u2&Hj&~v%`>9)E!2KRu4>2lr5(f7vKbU@wbvdi
zw0mXld1{GtT_-WoSn*do-X+Su`|zmnpMgiGf4V3?E1vXTORr^INqZuW2jo?0_#DMJ
z5yII~`5bOj(>n#mAB`-H_dyn=(r~xg8_8IXOYbp9gXwY^wV9oBp6phr-ES(FpnYdt
zbju4>O9wGyN%vanHCycK7@vjFZYs5EiEKx1)O1|Ncc);%;Q2~EnXd8I7C#$d4TQH5
zYpqdZ)vb1`lvtvLjwdlzyWJ%zRdOJ!_Y#zzxVioBZ{ignfT@G~(c?Z7*{@5;C`$FJ
zu1XnC)K%m()iWIzyj7oh-5k`O%!x`;qD35PD1@acB@tB-L`fY+!d%tLk)a=fkf7I=
z+8*rAGq%>mC!pFQsEV%gMTO*Uq8n)6XiBG2giJLeA3h<Wz&qBHEjzX<9Ea4<$283a
zS8H35uZvCnFDYy`%a^zt?e-?>FN>1WXjPF;UF+jXxpB7MQ4E8xX}Nq6ox7D&j#0xd
zLuUodtC>w&9Qe+)$kI^3nJ<28sSwb~5a3m~pPu*Z?F^|&xRP6poDKD&<9bVPY^620
zxvy0h`?<19nx}}xLs&LbrZwR$m%`Q=+0vAIJ?gcx3^SZ<GB>;CqZV^!8c`bUC(uyn
zH3cFtFNS#2Hk4qBWjPK@fuym&mWs6WILSn}lu^KEDAHO{M_6n4G>BM<Se<4o6(O#&
z(p7|*lpNOTM&{I2W^#@cLc*;!Th2DwiKt-9@J|Xi3Y-gBT;}_9$k|09!ss)#nVatc
zyhiJcXCsEJ#%<Iua(ALQu3of@3KT?UGsK*QiWy3_v0oUiB-CXwh+PoW55K<1;9|_v
zELAPnK`Yvf>LmPQT`y$8uMok4^8qHflX>K?f<2-pFKj5t{XXCN6W>YU>#p2yn4+ff
zp;ld&EpcJ7cIy&yKAIlmh}$v`ocvDN&(<_K&15rf@J`cd&m{|t=L=+_D3>>I+Z(QX
zA=9a-ro)i&-oe_iUSRVQqp^7DL@+%ngl@FmN9{Kjs+W369nw;x^c~ZUYa_O3Wp>Pq
zo(n6pZ5u6vBW0OJDWb(4lI2R7i&iWwQ9_57*;Qi25?cMn%e{QZ_%UfeD-w){X8KJ-
zRQAurhxD5T%TL7k4?XZ5l3Q(7qKQjG*(zX-)$W5kn$Tdui+!Z2l_UOH7bUc!<d&Zq
z_LN%4T*SqL6<Qy@syqjZ{xwYPC%b9sJ$i%lm#OYj`0chvaj@Zkvz*BPCRUp$+ikX*
z%nj8RK1(``OkRtPLLu|lzk&a^*n3x}dsq3sLo-SG@6~yaL~Rb?D~U&P+$e-|9I}J+
nJmi#7LWxV$D56B6@*azj(tFm2=5=2E|3dCarwS4siEJ0Z7ZfK7

literal 0
HcmV?d00001

diff --git a/Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1-patches.tgz b/Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1-patches.tgz
new file mode 100644
index 0000000000000000000000000000000000000000..4b43f535e86d9160d5a765d3cf8547122644d890
GIT binary patch
literal 368
zcmV-$0gwJ4iwFSWMW$8&1MSvNPlGTR2JoHv6tD4!1xgFd8~!<OegH3p7FRQ2aTxdU
z1vZULomsL;7N6gNhO|K8<)JK8ozKkDA01H;1W6Q8*T(CXhe6lABOb;PmoiL3K~1mZ
z(TJjBPU_vuvR2Q{R30m{bDYvow%pObxsQ+bL@YM-FRN<7l&5V`9Q+#1^N6MVx&A`5
z^%pV`qIm~+Q-3K1A5n1dnSA4)*S{?|G4^0<QvTd#W@U1JGM(O0*4uS#sm+SALTe>+
z&ojYTj|)k>%eKQ9+dAHHU3dE&X-bS=gygoHG<E3w%+GA;XKFcfn8{}qb>r@7Qc-DM
z=e9JYYBHs!s-VKojpKI1uC8xxcMco+xt@w%{<DGdA0q!l`IP@&`uEKKm*gY&r=ges
ze3<-)NwoF<C#8&$|G%*3`oD?3=LwS)*`+@C`u}Ud*WZD5xo{A6000000000000000
OfW9|GO#ib0C;$M=9=pc?

literal 0
HcmV?d00001

diff --git a/Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1.tbz b/Library/Homebrew/test/support/fixtures/tarballs/testball2-0.1.tbz
new file mode 100644
index 0000000000000000000000000000000000000000..c7e1af1f4e7bb9d96282e4af1e9334f02c6d4840
GIT binary patch
literal 1318
zcmV+>1=;#ST4*^jL0KkKS?cjPK>!7C|NsBr{r&v+|IPOA|NsC0-|ot5=HLWKKvaA=
zL;_AmM48Y8Y@iiD$rQk3f=^V+drEsMJx@`+Q%_I>)HDM_N09*2O+7|{&@|96o}d{3
z8UO$ur>UUz8z?d;(Ke<`i1gHD0LW+n4Ky?lPyo;X{ZIe^001744^U_T01_e*5YnDg
zGA3$zC#c9|$iiYV8UqtXngc<j)BtE=4Kg&yGz|a%03g7cG|<ycF)=hW(?bCm1YrS_
z0W{HofG_}=7zEQG82~X2G7w-*8fa;zn3$RxX`z6O0x*EdfSPE)Ko|f_i~?zp41gGh
znG9Sp=6+8j)bPo=nR$NK(;8Dn&HpN!1ZPa7#|GJ2DOzdk60nI8j*)6SODjnmZ5e`H
zLvU`}8*pZwXotmNoXln-j1lE9BR4><hbNZ!x!D>T%dt$;2^un%os?iYC;+4nW7|O+
zYuv_zt;D^`PKIi%+SRcX1L#4Mb|@^7I@zqg`(|w;YUu_dQl_F1bUnD>lL$S_qj|rL
zbH-r0YZEJSz!#afge{(<ER>e%>2$D&X=7DF38keb={q?<Ou{O}l^ifDFqF2yZ3AEy
zw9Or$fU`ogEfAXsV3L7?5zVv!E*A@AL>w(s!(hNO91=a0h!CEZ1<9SW+wL7ubyvb=
zA$F`@yF12#Hj)-QTivevSE=9*$zl4n_)0CiOAS9s%}ET-ctc~=$Q!5AwavaXnLKGb
zc2)mP2l~WF8Bwigp@uolX!EprT7D$icx@OSng4gd7@KDeoHimrG<d51#G)-wa4I!m
z6X!r=zw!FjVA2vEfhWGJmP52%Yip7<X&aDTfWfiXF!ESul8(pGy6xQ@uS;=LEU^f1
zG&shF9lEJtq>Mk9<n?h>Gf(*)rKc+DDBH<k6?3zIA4HBuewzgxxQ{)H%aF)XBdi$9
zK^`YT$@TZyC<9oL$OQrbsz(_ii5#;#mCBDd-Q)2h^o%JP4K|QMLrBU%*_W@_T3%Fa
zBIJ>CNZ9dEudWLU1ndg&Kt={FYob)7+SN#$4x)2<tO=~zgrfIsYvs<$*NC;7mis(L
zHARnrxWiVWW<wY-Or%)@Fxu$8$w4S|Q#UzRR4S2iCB<5GTzyGYBs~DtINR?NEGJ0X
z=H^d?O}W86++CKQ{_ZL7RsoHq;P6DDmahg9cJ5d#zW~UIgNhI{dK6W3D9wJMXsl%|
zKh6B-l4O|*PRpM&-n_-R^S;c1RAJ)7VETwQk?PEFBGabe$WvVH6y#TU?8g@4)9I=W
z`M$up=@7THNXOI>iy)B|pnZ3WP#FA-&HOFJJ%S{V-x3)MWT5;ZWdN&Vd_7G-G6#}X
zNdy=Yi)$^aFffGaCJ0~;Tt?h7Ist8Pz~zKla!BxcYOV`vzJ$8CnwW?{EGoHj2w@_z
zqzvgw-g@p&4^z^8**Tf{_z>9EJ2JqcGK-pww<fB%vgrvLty)4Pigf^8F+ie)J2fK?
zv^A)ZGu%elDa1ov$0HIFBPohC8G7m^-a0~IT8x?KZryyu0YXI|RcI(-=n^W!L{k8<
z<q%{h76IXZ6>f*_=<c#eA)6~7pHa4EpdVx-b2cv?eyTwX;Sxeb>G~pYEm(*y1uKdy
zyX(1OsCsJsWYuVIV}7yt$h{QnG+rSl!c9OjDBpL5WRmlB)s`d630d4xFWY_Q@W&B_
cg>Y-RXe-gKzyLNa6hGqbNT&)C9bP90An0{a=>Px#

literal 0
HcmV?d00001

diff --git a/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb b/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
index 1d7edccdea..8c5c1740d2 100644
--- a/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
+++ b/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
@@ -134,10 +134,12 @@ RSpec.shared_context "integration test" do # rubocop:disable RSpec/ContextWordin
                          bottle_block: nil, tab_attributes: nil)
     case name
     when /^testball/
+      # Use a different tarball for testball2 to avoid lock errors when writing concurrency tests
+      prefix = (name == "testball2") ? "testball2" : "testball"
       tarball = if OS.linux?
-        TEST_FIXTURE_DIR/"tarballs/testball-0.1-linux.tbz"
+        TEST_FIXTURE_DIR/"tarballs/#{prefix}-0.1-linux.tbz"
       else
-        TEST_FIXTURE_DIR/"tarballs/testball-0.1.tbz"
+        TEST_FIXTURE_DIR/"tarballs/#{prefix}-0.1.tbz"
       end
       content = <<~RUBY
         desc "Some test"